88 terms

What is life? A Guide to Biology: Chapter 3 (EXAM #1)

Cells
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Terms in this set (...)

Cell
The smallest unit of life that can function independently and perform all the necessary functions of life, including reproducing itself.
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, pre-existing cells.
Eukaryotic cell
has a central control structure called a nucleus, which contains the cell's DNA
Eukaryotes
An organism composed of eukaryotic cells. (good - kernel).
Prokaryotic cell
Does not have a nucleus; it's DNA simply resides in the cytoplasm
Prokaryote
An organism consisting of a prokaryotic cell (all prokaryotic cells are one celled organisms).
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 the cell membrane.
Cytoplasm
Cell's contents contained within the plasma membrane
Ribosomes
little granular bodies where proteins are made
Cell wall
Protects and gives shape to the cell
Flagellum (flagella)
Long, thin, whip-like projection of the plasma membrane that rotates like a propeller and moves the cell through the medium in which it lives
Pili (pilus)
A thin, hair-like projection that helps a prokaryote attach to surfaces
Nucleus
a membrane-enclosed structure that contains the cell's genetic material in the form of DNA.
Organelles
are enclosed separately within their own lipid membranes
Endosymbiosis Theory
Provides the best explanation for the presence of two organelles in eukaryotes: chloroplasts in plants and algae, and mitochondria in plants and animals
Chloroplast
The organelle in plant and eukaryotic algae cells in which photosynthesis occurs
Invagination
The folding in of a membrane or layer of tissue so that an outer surface becomes in inner surface
Phospholipids
A lipid that is the major component of the plasma membrane
Glycerol
A small molecule that forms the head region of a triglyceride fat molecule.
Polar
Having an electrical charge.
Hydrophilic
Molecules that can mix with water--("water loving") molecules.
Non-polar
Electrically uncharged
Hydrophobic
Carbon-hydrogen chains are non-polar molecules because they have no electrical charge and because they are non-polar, these molecules do not mix with water ("water fearing")
Phospholipid bilayer
The structure of the plasma membrane
Transmembrane Proteins
A protein that can penetrate a lipid bilayer of a cell's plasma membrane.
Surface proteins
A protein that resides primarily on the inner or outer surface of the phospholipid bilayer which constitutes the plasma membrane of the cell.
Receptor proteins
Surface or transmembrane proteins that bind to chemicals in the cell's external environment
Recognition proteins
Surface or transmembrane proteins that give each cell a "fingerprint" that makes it possible for the body's immune system to distinguish the cell's that belong inside your body from those that are invaders and need to be attacked
Transport proteins
Transmembrane proteins that help polar or charged substances pass through the plasma membrane
Enzymatic proteins
A that protein that initiates and accelerates a chemical reaction in a living organism enzymatic proteins take a part in chemical reactions on the inside and outside surfaces of the plasma membrane.
Cholesterol
Helps the membrane maintain its flexibility, preventing the membrane from becoming too fluid or floppy at moderate temperatures and acting as a sort of antifreeze, preventing the membrane from becoming too rigid at freezing temperatures
Membrane enzymes
Surface or transmembrane proteins that accelerate chemical reactions on the plasma membrane's surface
Mitochondrion
The organelle in plant and animal cells that converts the energy stored in food into a form usable by the cell
Endocytosis
To absorb large particles, such as bacterial invaders, cells engulf them with their plasma membrane
Exocytosis
To export large particles, such as digestive enzymes manufactured for use elsewhere in the body
Vesicle
A small, membrane-bound sac within a cell
Phagocytosis
relatively large particles are engulfed by the plasma membrane
Pinocytosis
Cells taking in dissolved particles and liquids
Receptor-mediated endocytosis
receptors on the surface of a cell bind to specific molecules
Tight junctions
Form continuous, water-right seals around cell's and also anchor cells in place
Desmosomes
Spot welds or rivers that fasten cell's together into strong sheets
Gap junctions
Pores surrounded by special proteins that form open channels between two cells
Nuclear membrane
A membrane that surrounds the nucleus of a cell, separating it from the cytoplasm
Chromatin
A mass of long, thin fibers consisting of DNA and proteins in the nucleus of the cell.
Nucleolus
An area near the center of the nucleus where subunits of the ribosomes are assembled.
Cytoskeleton
Gives animal cells shape and support; controls the intracellular traffic flow, serving as a series of tracks on which a variety of organelles and molecules are guided across and around the inside of the cell; it gives all cells some ability to control their movement.
Cilia (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.
Mitochondria (Mitochondrion)
"The powerhouse of the cell" because they generate most of the cell's supply of adenosine triphosphate (ATP), used as a source of chemical energy. In addition to supplying cellular energy, these organelles are involved in other tasks, such as signaling, cellular differentiation, and cell death, as well as maintaining control of the cell cycle and cell growth.
Intermembrane space
In mitochrondrion, the region between the inner and outer membranes.
Matrix
In a mitochondrion, the space within the inner membrane, where the carriers NADH and FADH2 begin the electron transport chain by carrying high-energy electrons to molecules embedded in the inner membrane.
Lysosomes
Round, membrane-enclosed, acid-filled vesicles that function as garbage disposals and are filled with about 50 different digestive enzymes and a super-acidic fluid, a corrosive broth so powerful that if the organelle were to burst, it would almost immediately kill the cell by rapidly digesting all of its component parts.
Endomembrane system
A system of organelles (the rough endoplasmic reticulum, the smooth endoplasmic reticulum, and the Golgi apparatus) 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.
Rough Endoplasmic Reticulum (rough ER)
A large series of interconnected, flattened sacs (they look like a stack of pancakes) that are connected directly to the nuclear envelope. It is called "rough" because its surface is studded with little bumps. These bumps are protein-making machines called ribosomes, and generally cells with high rates of protein production have large number of ribosomes.
Smooth Endoplasmic Reticulum
Synthesizes lipids such as fatty acids, phospholipids, and steroids and detoxifies molecules such as alcohol, drugs, and metabolic waste products.
Golgi apparatus
Processes and packages proteins, lipids, and other molecules for export to other location in or outside of the cell.
Central Vacuole
In plants, a large, fluid-filled organelle, surrounded by a membrane, important in nutrient storage, waste management, predator deterrence, sexual reproduction, and physical support.
Turgor pressure
In plants, the pressure of the contents of the cell against the cell wall, which is maintained by osmosis as water ruches into the cell when it contains high concentrations of dissolved substances; turgor pressure allows non-woody plants to stand upright, and its loss causes wilting.
Stroma
In the leaf of a green plant, the fluid in the inner compartment of a chloroplast; which contains DNA and protein making machinery.
Thylakoids
Interconnected membranous structures in stroma of a chloroplast, where light energy is collected and the conversion of light energy to chemical energy is photosynthesis takes place.
Passive transport
Molecular movement that occurs spontaneously, without the input of energy, the two types of passive transport are diffusion and osmosis.
Vacuole
Functions to store nutrients, retain and degrade waste products, accumulate poisonous materials, provides physical support, and in plants, contains pigments that enable plants to attract birds that help the plant reproduce.
cytosol
the jelly-like fluid and the cell's genome.
mitochondrion
the organelle in plant and animal cells that converts the energy stored in food into a form usable by the cell
Dehydration Synthesis
Dehydration synthesis is the process of joining two molecules, or compounds, together following the removal of water. When you see the word dehydration, the first thing that may come to mind is 'losing water' or 'lacking water.' This is a perfect way to remember what occurs during a dehydration reaction.
Hydrolysis
ydrolysis, the opposite of condensation, is a chemical reaction in which water breaks down another compound and changes its makeup. Most instances of organic hydrolysis combine water with neutral molecules, while inorganic hydrolysis pairs water with ionic molecules, such as acids, salts and bases.
saccharides
Sugar!
DNA
Uses deoxyribose sugar
•Very stable mlcl.
•Genes made of DNA
RNA
Uses ribose sugar•Breaks down easily•Transfers information from DNA to protein
Nitrogen containing bases DNA
DNA
1.Adenine (A)
2.Guanine (G)
3.Cytosine (C)
4.Thymine (T)
Nitrogen containing bases RNA
1.Adenine (A)
2.Guanine (G)
3.Cytosine (C)
4.Uracil (U)
Chargaff's Rule
•T=A
•C=G
Nucleotide Chain
(NSP)
Nitrogenous Base
Sugar 5
Phosphate Group
Base Pair
where two bases meet
<3
What is Life? 6 parts
1.Complex organization
2.Growth & Development
3.Metabolism
4.Reproduction
5.Heredity
6.Homeostasis
3 Major Types of Cells
•Bacteria
•Eukaryotes
•Archaea
"Prokaryotes
Bacteria & Archaea
Usually lumped together
Surface to Volume Ratio
Alka-celtcer
Osmosis with an Artificial Membrane
Osmosis in Cells Red Blood Cell
---->Hypertonic Solution <----
H2O leaves the Cell shriveling in up
Osmosis in Cells Red Blood Cell
---->Isotonic Solution <----
Equal water coming in and out the cell
Osmosis in Cells Red Blood Cell
---->Hypotonic Solution <----
H2O rushes into Red blood cell and pops it !
Osmosis in Plant Cells
---->Hypotonic Solution <----
Expands the Cell wall the cell becomes turgid! versus wilted.
Osmosis in Plant Cells
---->Hypertonic Solution <----
We see the cell wall retains its shape but the cytoplasm begins to shrink up.
Osmosis in Plant Cells
---->Isotonic Solution <----
cell maintains its normal shape
Cell membranes are selectively_____________
Permeable
Parts of Cell Membranes (3 Parts)
Phospholipid bilayer major part of cell membranes
•Polar heads & non polar tails
•Hydrophobic region stops large water soluble mlcls
Support fibers
rope-like proteins support cell proteins support cell shape
ID Tags
Different carbohydrate chains carbohydrate chains "label" different cell "label" different cell types