309 terms

Biology midterm 2013

Prentice Hall midterm
organisms such as plants, which make their own food from sunlight or chemicals
organisms, such as animals, that obtain energy from the foods they consume
Where do plants get the energy they need to produce food?
Plants and some other types of organisms are able to use light energy from the sun to produce food.
What is the role of ATP (adenosine triphosphate) in cellular activities?
ATP is used by all types of cells as their basic energy source.
process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches
What did the experiments of van Helmont, Priestly, and Ingenhousz reveal about how plants grow?
In the presence of light, plants transform carbon dioxide and water into carbohydrates, and they also release oxygen.
What is the overall equation for photosynthesis?
carbon dioxide + water —> sugars + oxygen
What is the role of light and chlorophyll in photosynthesis?
Light is a form of energy and chlorophyll absorbs light and the energy from the light.
principal pigment of plants and other photosynthetic organisms; captures light energy
Plants gather the sun's energy with light-absorbing molecules are called...
What happens in the light-dependent reactions?
... use energy from sunlight to produce ATP, NADPH, and oxygen. It takes place within the thylakoid membranes of chloroplasts.
What is the Calvin cycle?
... uses ATP and NADPH from the light-dependent reations to produce high-energy sugars. It takes place in the stroma of chloroplasts and does NOT require light.
saclike photosynthetic membranes found in chloroplasts
Proteins in the thylakoid membrane organize chlorophyll and other pigments into clusters known as...
the region outside the thylakoid membranes in chloroplasts
(nicotinamide adenine dinucleotide phosphate) one of the carrier molecules that transfers high-energy electrons from chlorophyll to other molecules.
light-dependent reactions
reactions of photosynthesis that use energy from light to produce ATP and NADPH
ATP synthase
large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP
Which are autotrophs?
plants, mushrooms
One of the principal chemical compounds that living things use to store energy is...
Which scientist concluded that most of a growing plant's mass comes from water?
van Helmont
In addition to light and chlorophyll, photosynthesis requires...
water and carbon dioxide
The leaves of a plant appear green because chlorophyll...
reflects green light
The products of photosynthesis are...
sugars and oxygen
The first process in the light-dependent reactions of photosynthesis is...
ATP formation
Which substances from the light-dependent reactions of photosynthesis is a source of energy for the Calvin cycle?
The light dependent reactions of photosynthesis are also known as the...
Calvin cycle
How do heterotrophs and autotrophs differ in the way they obtain energy?
heterotrophs obtain energy from the food they eat.

autotrophs obtain energy from the sunlight
Describe the three parts of an ATP molecule.
3 Phosphate groups
Use the analogy of battery to explain how energy is stored in and released from ATP.
ATP can be compared to a fully charged battery because both contain stored energy.
Compare the amounts of energy stored by ATP and glucose. Which compound is used by the cell as an immediate source of energy.
- A single molecule of the sugar glucose stores more than 90 times the chemical energy of a molecule of ATP.
- ATP is used as an immediate source of energy.
How were Priestley's and Ingenhousz's discoveries about photosynthesis related?
They both showed that light was necessary for plants to produce oxygen.
Write the basic equation for photosynthesis using the names of the starting and final substances of the process.
6CO2 + 6H20 —> C6H12O6 + 6O2
carbon dioxide + water —> sugars + oxygen

(NOTE: —> is light)
What role do plant pigments plan in the process of photosynthesis?
They gather the sun's energy
Explain the role of NADP+ as an energy carrier in photosynthesis.
It transfers high-energy electrons from chlorophyll to other molecules.
What is the role of ATP synthase? How does it work?
they provide the energy to build energy - containing sugars from low - energy compounds.
It allows hydrogen ions out of the thylakoid
Summarize what happens during the Calvin cycle.
plants use the energy that ATP and NADPH contain to build high-energy compounds that can be stored for a long time.
How do the events in the Calvin cycle depend on the light-dependent reactions?
The Calvin cycle uses ATP and NADPH from the light-dependent reactions to produce high-energy sugars.
Describe three factors that affect the rate at which photosynthesis occurs.
- water
- temperature
- intensity of light
the ability to do work
All living things require...
Autotrophs are plants and some other types of organisms are able to use ________ from the sun to produce _________.
- light energy
- food
Plants and some other types of organisms are able to use light energy from the sun to produce food.
organisms that obtain their energy from food they consume
Energy comes in many different forms. Give examples.
- light
- heat
- electrically
- chemical compounds
Living things use chemical compounds stored and released in cells called...
ATP or adenosine triphosphate
ATP (adenosine triphosphate) contains...
a 5 carbon sugar (ribose) & 3 phosphates
ATP (adenosine triphosphate)
ADP lacks the third phospate make it ...
Cells store the ______ until energy is needed by adding the third phosphate.
When the bond is broken between the 2nd and 3rd phosphate, ______ is released.
The release of energy when the bond is broken between the 2nd and 3rd phosphate power these functions:
- active transport
- muscle contractions
- protein synthesis
The characteristics of ATP make it exceptionally useful as the basic _____ source of cells.
ADP + phosphate —>(energy)—> ATP
Active transport
Sodium (Na) Potassium (K) pump maintaining ions on both sides of the cell
Cells only keeps a small amount of _____ .
- ATP does not store easily
________ stores 90 times more chemical energy than a molecule of ATP.
When plants use the energy of sunlight to convert water and carbon dioxide into high-energy carbohydrates (sugar and starches) and a waste product (oxygen).
scientist who concludes the trees gain most of their mass from water
scientist who finds that plants release oxygen
scientist who finds that aquatic plants produce oxygen bubbles in the light but not in dark. Conclusion: plants need light to produce oxygen
scientist who proposed plants convert light energy into chemical energy
scientist who traces chemical path that carbon follows to form glucose (Calvin cycle)
scientist who describes the process of electron transfer from molecule to electron transport chain
Photosynthesis Equation
- Reactants —> Products
- Carbon Dioxide + water in the presence of light yields sugars & oxygen
In addition to water and carbon dioxide, photosynthesis requires ________ and _________, a molecule in chloroplasts.
light and chlorophyll
Light is in ___________ form and creates a spectrum from ________ to ______.
- wavelength form
- violet to red
light absorbing molecules in plants
the principle pigment in plants
2 main types of chlorophyll:
chlorophyll a & chlorophyll b
__________ (green) absorbs the blue-violet and red ends of the spectrum and transfers it to the electrons. While other pigments like __________ absorb the other color.
- Chlorophyll
- carotene
Where does photosynthesis take place?
in chloroplasts
Chloroplasts contain tiny sacs like photosynthetic membranes called...
Thylakoids are arranged in stacks known as ...
Pigments are arranged into clusters known as ...
What are the light collecting units in the chloroplasts?
photosystems (clusters of pigments)
What are the 2 Photosystems reactions?
- (1) light dependent (takes place in the thylakoids)

- (2) light independent or Calvin cycle (takes place in the stroma - the region outside the thylakoid membranes)
Sunlight excites the electrons in ________.
The excited electrons and their energy must be transported by an electron carrier, like _______. This electron carrier can hold ______ electrons and an ion of _________. It is converted into _________ which is trapping sunlight energy into _______ energy. This is the electron ________ _______.
- 2 electrons
- hydrogen (H+)
- chemical energy
- electron transport chain
Light dependent reactions produce _______ ________ and convert _____ and _______ into the energy carriers ______ and _______.
... oxygen gas and convert ADP and NADP+ into the energy carriers ATP and NADPH.
Light independent cycle
takes in the stroma and outside the grana
The Calvin cycle uses ______ and ______ from the light-dependent reactions to produce high energy sugars.
3 factors that affect photosynthesis:
- water supply
- temperature
- intensity of light
organized way of using evidence to learn about the natural world; also, the body of knowledge that scientists have built up after years of using this process
use of one or more of the senses-sight, hearing, touch, smell, and sometimes taste - to gather information
evidence; information gathered from observation
logical interpretation based on prior knowledge and experience
possible explanation for a set of observations or possible answer to a scientific question
spontaneous generation
hypothesis (disproven) stating that life could arise from non-living matter.
controlled experiment
a test of the effect of a single variable by changing it while keeping all other variables the same
manipulated variable
factor in an experiment that a scientist purposely changes; also knows as independent variable.
responding variable
factor is an experiment that a scientist wants to observe, which may change in response to the manupulated variable; also known as a dependent variable.
well-tested explanation that unifies a broad range of observations.
Science that seek to understand the living world.
Collection of living matter enclosed by a barrier that separates the cell from its surroundings; basic unit of all forms of life.
Process by which organisms maintain a relatively stable internal environment.
Sexual reproduction
Process by which cells from two different parents unite to produce the first cell of a new organism
Asexual reproduction
Process by which a single parent reproduces by it self
Set of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes.
A signal to which an organism responds.
Metric system
decimal system of measurement based on certain physical standards and scaled on multiples of 10
Device that produces magnified images of structures that are too small to see with the unaided eye.
Compound light microscope
Microscope that allows light to pass through a specimen and uses two lenses to form an image.
Electron microscope
Microscope that forms an image by focusing beams of electrons onto a specimen.
Cell culture
group of cells grown in a nutrient solution from a single original all.
Cell fractionation
Technique in which cells are broken into pieces and the different cell part are separate
the basic unit of matter
subatomic particles
protons, neutrons and electrons
positively charged particles in the nucleus
particles with no charge in the nucleus
negatively charged particles in constant motion outside the nucleus
why atoms are uncharged
atoms have equal numbers of protons and electrons
chemical element
a pure substance that consists entirely of one type of atom
atomic number
the number of protons in an atom of an element
atoms of the same element that differ in the number of neutrons
substances formed by the chemical combination of two or more elements in definite proportions
chemical formula
shorthand to show the chemical composition of a compound
chemical bonds
hold atoms in compounds together; the main types are ionic and covalent
ionic bond
a bond formed when one or more electrons are transfered from one atom to another
a positively or negatively charged atom
covalent bond
a bond formed when electrons are shared between atoms
a structure that results when atoms are joined together by covalent bonds; the smallest unit of most compounds
van der Waals forces
intermolecular forces of attraction between the oppositely chargeed regions of nearby molecules
H2O; the greatest solvent on earth
oxygen end of the water molecule
slight negative charge because it pulls the electrons more
hydrogen end of the water molecule
slight positive charge because it has less attraction for the electrons
polar molecules
molecules in which the charges are unevenly distributed; they can attract each other
attraction between molecules of the same substance
attraction between molecules of different substances
material composed of two or more elements or compounds that are physically mixed together but not chemically combined
a mixture in which all the components are evenly distributed throughout the mixture
the substance in a solution that is dissolved
the substance in a solution in which the solvent dissolves
ions formed by water molecules
hydrogen ion (H+) and hydroxide ion (OH-)
mixtures of water and nondissolved material
a suspension of water, cells, and undissolved particles that moves through the body
pH 7
pH of pure water
pH scale
a measurement system to indicate the concentration of H+ ions in solution
a compound that forms H+ ions in solution
pH above 7
pH below 7
a compound that produces OH- ions in solution
weak acids or bases that can react with strong acids or bases to prevent sharp, sudden changes in pH
organic chemistry
the study of all compounds that contain bonds between carbon atoms
organic compounds
carbon compounds
carbon's valence electrons
reasons carbon is important
can make covalent bonds with other atoms (4 valence electrons); can bond to other carbon atoms to make long chains
polymers; molecules made from thousands or even hundreds of thousands of smaller molecules
a process that forms macromolecules by joining smaller compounds together to form larger ones
small units that join together to form macromolecules, or polymers
four groups of organic compounds in living things
carbohydrates, lipids, nucleic acids, proteins
used as the main source of energy; used in structures for plants and some animals
examples of carbohydrates
starches and sugars
used in living things to store energy; in biological membranes and coverings
examples of lipids
fats, oils and waxes
fatty acids and glycerol
compounds that make up lipid molecules
nucleic acids
store and transmit hereditary (genetic) information
elements in nucleic acids
hydrogen, oxygen, nitrogen, carbon, phosphorus
elements in lipids
carbon and hydrogen
elements in carbohydrates
carbon, hydrogen, oxygen
monomers that make up nucleic acids
nucleotides are made of
5-carbon sugar; phosphate group; and nitrogenous base
ribonucleic acid
deoxyribonucleic acid
can be broken down for immediate energy
complex carbohydrates (polymers) where extra sugar is stored
simple sugars (glucose, galactose (from milk), fructose (from fruit))
large macromolecules formed from monosaccharides
animal starch that can be released from the liver when blood glucose is low
polymers of amino acid macromolecules that control the rate of reactions, regulate cell processes, form bone and muscles, transport substances in and out of cells, or help fight disease
proteins are made of
nitrogen, carbon, hydrogen, oxygen
amino acids
compounds with an amino group (NH2) on one end and a carboxyl group (COOH) on the other
chemical reaction
a process that changes one set of chemicals (reactants) into another set of chemicals (products) by breaking bonds and forming new ones
the elements or compounds that enter into a chemical reaction
the elements or compounds produced by a chemical reaction
spontaneous reactions
reactions that release energy
nonspontaneous reactions
reactions that absorb energy and will not occur without a source of energy
activation energy
the energy that is needed to get a reaction started
a substance that speeds up the rate of a chemical reaction
how catalysts work
they lower the activation energy for a reaction
proteins that act as biological catalysts and speed up reactions by lowering activation energy
reactants in an enzyme-catalyzed reaction
active site
a site on an enzyme where the substrate binds
The scientific study of interactions among organisms and between organisms and their environment, or surroundings.
Contains the combined portions of the planet in which all of life exists, including land, water, and air (atmosphere)
Group of organisms so similar to one another that they can breed and produce fertile offspring.
Group of individuals that belong to the same species and live in the same area.
Assemblage of different populations that live together in a defined area.
A collection of all the organisms that live in a particular place together with their nonliving, or physical, environment.
Group of ecosystems that have the same climate and similar dominant communities.
Organisms that capture energy from the sunlight or chemicals and use it to produce it's own food from inorganic materials.
Organism that can capture energy from sunlight or chemicals and use it to produce food from inorganic compounds.
Process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates such as sugars and starches.
Process by which some organisms, such as certain bacteria, use chemical energy to produce carbohydrates.
Organism that relies on other organisms for their energy and food supply.
Heterotrophic organism that feeds on other organisms in a food chain
Obtains energy by eating only plants.
Eats animals.
Eats both plants and animals.
Feeds on plants and animal remains (dead matter)
Breaks down organic matter.
Food Chain
A series of steps in which organisms transfer energy by eating and being eaten.
Food Web
Network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem.
Trophic Level
Each step in a food chain or food web.
Ecological Pyramid
Diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web.
The total amount of living tissue within a given trophic level.
Biogeochemical Cycle
Process in which elements, chemical compounds, and other forms of matter are passed from one organism to another and from one part of the biosphere to another.
The process by which water changes from liquid form to an atmospheric gas.
Loss of water from a plant through it's leaves.
All the chemical substances that an organism needs to sustain life.
Nitrogen Fixation
Process of converting nitrogen gas into ammonia.
Conversion of nitrates into nitrogen gas.
Primary Productivity
The rate at which organic matter is created by producers in an ecosystem.
Limiting Nutrient
Single nutrient that either is scarce or cycles very slowly, limiting the growth of organisms in an ecosystem.
Algal Bloom
An immediate increase in the amount of algae and other producers that results from a large input of a limiting nutrient.
basic unit of all forms of life
cell theory
idea that all living things are made of cells, cells are the basic units of structure and function in living things, and new cells come from existing cells
contains the cell's genetic material (DNA) and controls the cell's activities
unicellular organism lacking a nucleus
organism whose cells contain nuclei
mini organs within eukaryotic cell
material inside the cell membrane
nuclear envelope
layer of two membranes that surrounds the nucleus of a cell
DNA tightly coiled around proteins
containing the genetic information that is passed from one generation of cells to the next
creating RRNA for ribosomes
assembles proteins
rough endoplasmic reticulum
synthesizes proteins for export from the cell, rough from attached ribosomes
Golgi apparatus
modifies, sorts, and packages proteins and other materials for storage or deport
breaks down lipids, carbohydrates, and proteins into small molecules and breaks down old organelles
smooth endoplasmic reticulum
synthesizes proteins for export from the cell builds lipids
storage in the plant cell
converts the chemical energy stored in food into compounds that are more convenient for the cell to use
captures the energy from sunlight and converts it into chemical energy
maintain cell shape and cell movement
helps organize cell division in animal cell near the necleus
cell membrane
regulates what enters and leaves the cell and protection and support
Robert Hooke
used first microscope, discover cork cells in 1665
live specimen, not detailed
veiws surface of cells (non-living)
veiws internal structure (non-living)
cell wall
supporting layer around the cell membrane
lipid bilayer
core of cell membrane double-layered sheet
plant cell walls mostly made out of
mass of solute in a given volume of solution
molecules tend to move from an area where they are more concentrated to an area where they are less concentrated
diffusion of water through a selectively permeable membrane
when the concentration of a solute is the same throughout a solution
when the concentration of two solutions is the same
the solution with the greater concentration of solutes
the solution with the lesser concentration of solutes
facilitated diffusion
movement of specific molecules across cell membrane through protein channels
protein channel job
pass through specific molecules that cannot pass through membrane
active transport
using energy to move materials across membrane
passive transport
no energy needed to move materials across membrane
extra energy bank or battery for the cell created by mitochondrian
type of active transport, takes material into the cell by infolding the cell membrane
type of active transport, take in unwanted molecules, lysosomes kill them
type of active transport, moves large amounts of materials out of the cell by popping out vesicles
takes in liquid from surroundings
single-celled organism
cell specialization
the process in which cells develop in different ways to perform different tasks
group of similar cells that preform a function
group of tissues that work together to perform related functions
What is cellular respiration?
process that releases energy by breaking down glucose and other food molecules in the presence of oxygen
what happens during the process of glycolysis?
Glucose breaks down into two molecules of pyruvate
What are the two main types of fermentation?
- Alcoholic fermentation - Lactic acid fermentation
amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius
first step in releasing the energy of glucose, in which a molecule of glucose is broken into two molecules of pyruvic acid
cellular respiration
process that releases energy by breaking down glucose and other food molecules in the presence of oxygen
(nicotinamide adenine dinucleotide) electron carrier involved in glycolysis
process by which cells release energy in the absence of oxygen
process that does not require oxygen
Lactic acid fermentation
converts glucose into lactic acid
What happens during the Krebs cycle?
pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions
How are high-energy electrons used by the electron transport chain?
The electron transport chain is a critical component of the complex process by which your cells extract energy from sugars like glucose. It begins inside your cells' mitochondria with the tricarboxylic acid cycle (TCA), which reduces or adds electrons to molecules called NAD+ and FAD, turning them into NADH and FADH2. These molecules in turn pass the high-energy electrons on to the electron transport chain. The ensuing events are a little complicated, but the basic logic is easy to follow.
process that requires oxygen
Krebs cycle
second stage of cellular respiration, in which pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions
electron transport chain
a series of proteins in which the high-energy electrons from the Krebs cycle are used to convert ADP into ATP
What happens to pyruvic acid during the Krebs cycle?
During the Krebs cycle two molecules of pyruvic acid are converted in to acetyl-coa.
How does the electron transport chain use the high-energy electrons from the Krebs cycle?
to convert ADP into ATP
Describe the process of cellular respiration.
it breaks down glucose and other food molecules in the presence of oxygen
What are the products of glycolysis?
two molecules of pyruvic acid (a 3-carbon compound)
Name the two main types of fermentation.
- Alcoholic Fermentation - Lactic Acid Fermentation
In cells, the energy available in food is used to make an energy-rich compound called...
The first step in releasing the energy of glucose in the cell is know as...
The process that releases energy from food in the presence of oxygen is...
Cellular respiration
The net gain of energy from glycolysis is...
2 ATP Molecules
Because fermentation takes place in the absence of oxygen, it is said to be...
The Krebs cycle take place within the ...
The electron transport chain uses the high-energy electrons from the Krebs cycle to...
convert ADP into ATP
A total of 36 molecules of ATP are produced from 1 molecule of glucose as a result of...
cellular respiration
During heavy exercise, the buildup of lactic acid in muscle cells result in...
oxygen debt
Problems that growth causes for cells
The larger a cell becomes, the more demands the cell places on its DNA, and the cell has more trouble moving enough nutrients and wastes across the cell membrane.
How cell division solves problems of cell growth-
Before it becomes too large, a growing cell divides forming two new daughter cells. Each daughter cell gets its own complete copy of genetic information, solving the information storage problem. It also solves the problem of increasing size by reducing cell volume, because each daughter cell has an increased ratio of surface area to volume. This allows efficient changes with the environment.
Main Events of Cell Cycle
A cell grows, prepares for division, and divides to form two new daughter cells, each of which begins the cycle again.
First Phase of Mitosis
Prophase- the chromatin condenses into chromosomes. the centrioles separate, and a spindle begins to form. The nuclear envelope breaks down
Second Stage of Mitosis
Metaphase- the chromosome line up across the center of the cell. Each chromosome is connected to a spindle fiber at its centromere.
Third Stage of Mitosis
Anaphase- the sister chromatids separate into individual chromosomes and are moved apart.
Fourth Stage of Mitosis
Telophase- the chromosomes gather at opposite ends of the cell and lose their distinct shapes. two new nuclear envelopes will form.
Factor that can stop cells from growing-
Cells coming into contact with other cells
How a cell cycle is regulated-
Proteins have been found that help regulate the cell cycle. Internal Regulators- Allow the cell cycle to proceed only when certain processes have happened inside the cell.
External Regulators-
Direct cells to speed up or slow down the cell cycle.
How cancer cells are different from other cells-
They do not respond to the signals that regulate the growth of most cells.
G1 phase of the Cell Cycle (First Part of Interphase)
During this phase, cells increase in size and synthesize new proteins and organelles.
S phase of the Cell Cycle (Second Part of Interphase)
During this phase, chromosomes are replicated, the synthesis of DNA molecules takes place, and key proteins associated with the chromosomes are also synthesized. Usually, when a cell enters this phase and begins the replication of its chromosomes, it completes the rest of the cell cycle.
G2 Phase of the Cell Cycle (Third Part of Interphase)
During this phase, many of the organelles and molecules required for cell division are produced. This phase is the last part of Interphase, and once it is completed, the cell is ready for Cell Division
M Phase of the Cell Cycle
During this phase, the four parts of Mitosis happen (Prophase, Metaphase, Anaphase, and Telophase), along with Cytokinesis. Cytokinesis is when the cytoplasm pinches in half, leaving each daughter cell with an identical set of duplicate chromosomes, and usually happens at the same time as Telophase.
Fis protein found to regulate the timing of the cell cycle in eukaryotic cells. Since then, many other proteins have been found to do the same.