88 terms

Chapter 3 bio

vocab words
STUDY
PLAY

Terms in this set (...)

active transport
molecular movement that depends on the input of energy, which is necessary when the molecules to be moved are larger or are being moved against their concentration gradient
cell
the smallest unit of life that can function independently; a three-dimensional structure, surrounded by a membrane and in the case of prokaryotes and most plants, a cell wall, in which many of the essential chemical reactions of the life of an organism take place
cell theory
a unifying and universally accepted theory in biology that holds that all living organisms are made up of one or more cells, and that all cells arise from other, preexisting cells
cell wall
a rigid structure, outside the cell membrane, that protects and gives shape to the cell, found in many prokaryotes and plants
chloroplast
organelle thats the site of photosynthesis; contains thylakoids inside the stroma where the light is collected
cholesterol
one of the sterols, a group of lipids important in regulating growth and development, an important component of most cell membranes, helping the membrane maintain its flexibility
chromatin
thin fibers of DNA, which carry all hereditary information in the nucleus
cilium
short projections from the cell surface, often occurring in large numbers on a single cell, that beat against the intercellular fluid to move the fluid past the cell
cytoplasm
the jelly like fluid that fills the inside of the cell, in eukaryotes this contains organelles
cytoskeleton
a network of protein structures in the cytoplasm of eukaryotes that serves to aid in support and in some cases, give animal cells of different types their characteristic shapes. serves as a track guiding the intercellular traffic flow and is flexible and can generate force
diffusion
passive transport in which a particle is dissolved in a gas or liquid and moves from an area of higher solute concentration, to an area of lower solute concentration
endocytosis
a cellular process in which large particles, solid or dissolved, outside the cell are surrounded by a fold of the plasma membrane, and are enclosed which moves into the cell.
endomembrane system
a system of organelles that surrounds the nucleus, it produces and modifies necessary molecules, breaks down toxic chemicals and cellular by-products, and is thus responsible for many of the fundamental functions of the cell
endosymbiosis theory
theory of origin of eukaryotes that states; in the past, two different types of prokaryotes engaged in a close partnership and eventually one, capable of performing photosynthesis, was subsumed into the other. the smaller prokaryote made some of its photosynthetic energy available to the host, and over time, the two became symbiotic and eventually became a single more complex organism
enzymatic protein
a protein that accelerates intracellular and extracellular reactions on the plasma membrane
eukaryote
an organism composed of eukaryotic cells
eukaryotic cell
a cell with a membrane surrounded nucleus containing DNA, membrane surrounded organelles and internal structures organized into compartments
exocytosis
a cellular process in which particles within the cell, solid or dissolved, are enclosed in a vesicle and transported to the plasma membrane, where the membrane of the vesicle merges with the plasma membrane and the material in the vesicle is expelled to the extracellular fluid for use throughout the body
facilitated diffusion
diffusion of molecules through the phospholipid bilayer of the plasma membrane that takes place through a transport protein embedded in the membrane - molecules to big to cross the membrane directly or are electrically charged use this
flagellum
long, thin, whip like projection from the cell body of prokaryote that aids in cell movement through the medium in which the organism lives; in animals the only cell with this is sperm
fluid mosaic
describes the structure of the plasma membrane; which is made up of several different types of molecules, many of which are not fixed in place but float, held in proper orientation by hydrophilic and hydrophobic forces
gap junction
act like secret passageways and allow materials to pass between cells
glycerol
a small molecule that forms the head region of a triglyceride fat molecule
golgi apparatus
processes and packages proteins, lipids, and other molecules for export to other locations in or outside of the cell -modifies molecules and bud off as a transport vesicle
hydrophilic
attracted to water (head of a fatty acid chain)
hyrdophobic
repelled by water (tail of a fatty acid chain)
hypertonic
a solution with a higher concentration of solutes- water moves out of cell
hypotonic
a solution with a lower concentration of solutes-water moves into cell (animal cells may explode in this solution due to the lack of a cell wall)
intermediate filaments
durable, rope like systems of numerous overlapping proteins & gives cells great strength
invagination
the folding in of a membrane or layer of tissue so that an outer surface becomes its inner surface
isotonic
refers to solutions with equal concentrations of solutes- water movement is balanced
lysosome
acts as floating garbage disposals for cells, digesting and recycling cellular waste products and consumed material
matrix
the space within the inner membrane, where the carriers of NADH and FADH2 begin the electron transport chain by carrying high energy electrons to molecules embedded in the inner membrane
microfilaments
a protein fiber that are long, solid rod-like fibers and hlep with cell contraction and cell division
microtubules
a protein fiber that are thick hollow tubes and are tracks to which molecules and organelles within the cell may attach and be moved along
mitochondrion
in eukaryotic cells that acts as all-purpose energy converters, and harvests energy for cellular functions (contains DNA, matrix, outermembrane, innermembrane, and intermembrane space)
nonpolar
electrically uncharged
nuclear membrane
a membrane that surrounds the nucleus of a cell, separating it from the cytoplasm, consisting of two bilayers and perforated by pores enclosed in embedded proteins that allow the passage of large molecules from nucleus to cytoplasm and vise versa; also called the nuclear envelope
nucleolus
an area near the center of the nucleus where subunits of the ribosomes are assembled
nucleus
a membrane-enclosed structure in eukaryotic cells that contains the organisms genetic information as linear strands of DNA in the form of chromosomes
organelle
specialized structures in the cytoplasm of eukaryotic cells with specific functions, such as the rough and smooth endoplasmic reticulum
osmosis
type of passive transport where water diffuses across a membrane, in order to equalize the concentration of water inside and outside the cell
passive transport
molecular movement that occurs spontaneously, without the input of energy, the two types; osmosis & diffusion
phagocytosis
one of the three types of endocytosis, in which relatively large solid particles are engulfed by the plasma membrane
phospholipid
a lipid that is the major component of the plasma membrane; phospholipids are structurally similar to fats, but contain a phosphorous atom and have two, not three, fatty acid chains
phospholipid bilayer
the structure of the plasma membrane; two layers of phospholipids, arranged tail to tail, with the hydrophilic head regions facing the watery extracellular fluid and intracellular fluid
pilus
a thin, hair like projection that helps a prokaryote attach to surfaces
pinocytosis
one of the three types of endocytosis, in which dissolved particles and liquids are engulfed by the plasma membrane, a vesicle is formed, and the material is moved into the cell
plasma membrane
a complex, thin, two layered membrane that encloses the cytoplasm of the cell, holding the contents in place and regulating what enters and leaves the cell; also called cell membrane
plasmodesma
in plants, microscopic tube-like channels connecting the cells and enabling communication and transport between them
polar
having an electric charge
primary active transport
active transport using energy released directly from ATP
prokaryote
an organism consisting of a prokaryotic cell (single celled)
prokaryotic cell
a cell bound by a plasma membrane enclosing the cell contents; there is no nucleus or other organelles
receptor protein
protein in plasma membrane that bind to external chemicals in order to regulate processes within the cell
ribosome
granular bodies in the cytoplasm, released from their initial positions on the rough endoplasmic reticulum; that copy the information in segments of DNA to provide instruction for the construction of proteins
rough endoplasmic reticulum
modifies proteins that will be shipping to other locations in the endomembrane system or the cell surface or even outside the cell. is covered in ribosomes
secondary active transport
active transport in which there is no direct involvement of ATP; the transport protein simultaneously moves one molecule against its concentration gradient while letting another flow down its concentration gradient
simple diffusion
diffusion of molecules directly through the phospholipid bilayer of the plasma membrane that takes place without the assistance of other molecules, oxygen and carbon dioxide because they are so small and carry no charge can pass through the membrane this way
smooth endoplasmic reticulum
synthesizes lipids such as fatty acids, phospholipids, and steroids also detoxifies molecules such as alcohol, drugs and metabolic waste products - no ribosomes
solute
a substance that is dissolved in a gas or liquid; in a solution of water and sugar, sugar is the ......
solvent
the gas or liquid in which a substance is dissolved, in a solution of water and sugar, water is...
stroma
in the leaf of a green plant, the fluid in the inner compartment of a chloroplast, which contains DNA and protein making machinery
surface protein
a protein that resides primarily on the inner or outer surface of the phospholipid bilayer that constitutes the plasma membrane of the cell
thylakoid
interconnected membranous structures in the stroma of a chloroplast, where light energy is collected and the conversion of light energy to chemical energy in photosynthesis takes place
tight junction
form a water-tight seal between cells, like caulking around a tub
tonicity
for a cell in solution, a measure of the concentration of solutes outside the cell relative to that inside the cell
transmembrane protein
a protein that can penetrate the phospholipid bilayer of a cells plasma membrane
transport protein
a protein that provides a channel or passageway through which large or strongly charged molecules can pass.
turgor pressure
in plants, the pressure of the contents of the cell against the cell wall, which is maintained by osmosis; allows non-woody plants to stand upright, and its loss causes wilting
vacuole
stores nutrients, retains and degrades waste products/ accumulates poisonous materials- contains pigments enabling plants to attract birds and insects that help the plant reproduce and provides the cell with physical support
e
Which of the following statements about cell theory is correct?

a. all living organisms are made up of one or more cells

b. all cells arise from other, preexisting cells

c. all eukaryotic cells contain symbiotic prokaryotes

e. both a & b are correct
b
which of the following statements about prokaryotes is incorrect?

a. prokaryotes appeared on earth before eukaryotes

b. prokaryotes have circular pieces of DNA within their nuclei

c. prokaryotes contain cytoplasm

d. prokaryotes contain ribosomes

e. some prokaryotes can conduct photosynthesis
d
cellular "fingerprints":

a. are exposed on the cytoplasmic side of the membrane

b. are made from cholesterol

c. are "erased" by the HIV virus

d. can help the immune system distinguish "self" from "non self"

e. all of the above are correct
c
the movement of molecules across a membrane from an area of high concentration to one of low concentration is best described as:

a. active transport

b. inactivated transport

c. passive transport

d. channel-mediated diffusion

e. electron transport
a
the transport of water across a membrane from a solution of lower solute concentration to a solution of higher solute concentration is best described as:

a. osmosis

b. facilitated diffusion

c. receptor-mediated transport

d. active transport

e. general diffusion
d
which of the following allow the passage of small molecules between animal cells?

a. nucleoli

b. tight junctions

c. desmosomes

d. gap junctions

e. black holes
d
the cytoskeleton;

a. is a viscous fluid found in all cells

b. fills a cells nucleus but not the other organelles

c. gives an animal cell support and shape, but cannot control movement

d. helps to coordinate intracellular movement of organelles and molecules

e. all of the above are correct
c
Which of the following statements about mitochondria are correct?

a. mitochondria are found in both eukaryotes and prokaryotes

b. there tend to be more mitochondria in fat cells than in liver cells

c. most plant cells contain mitochondria

d. mitochondria may have originated evolutionarily as photosynthetic bacteria

e. all of the above are correct
e
which of the following organelles is not present in animals cells?

a. lysosomes

b. golgi apparatus

c. rough endoplasmic reticulum

d. mitochondrion

e. chloroplast
b
given that a cells structure reflects its function, what function would you predict for a cell with a large golgi apparatus?

a. movement

b. secretion of digestive enzymes

c. transport of chemical signals

d. rapid replication of genetic material and coordination of cell division

e. attachment to bone tissue
b
cell walls:

a. only occur in plant cells

b. are not completely solid, having many small pores

c. confer less structural support than the plasma membrane

d. dissolve when a plant dies

e. are made primarily from phospholipids
e
which of the following organelles is not found in both plant and animal cells?

a. nucleus

b. rough endoplasmic reticulum

c. mitochondrion

d. smooth endoplasmic reticulum

e. central vacuole
e
in plant cells, chloroplasts:

a. serve the same purpose that mitochondria serve in animal cells

b. are the sit of conversion of light energy into chemical energy

c. play an important role in the breakdown of plant toxins

d. have their own linear strands of DNA

e. both b & d are correct
carbohydrate chains
provide a "fingerprint" for the cell, so it can be recognized by other cells
desmosomes
act like velcro and fasten cells together (type of connection between animal cells)
centriole
What structure is not found in plant cells but is found in animal cells?
centriole
spindle fibers are connected at each pole to form this; inside the nuclear membrane