Biology 196 Unlv Nika ch1-4 Flashcards
(102 cards)
1
Q
Critical Surface area to volume ratio
A
A point where there is insufficient membrane to allow transport of enough nutrients.
2
Q
Light microscopy
A
Cell illumination with light, light refracted by lenses to magnify.
3
Q
Electron microscopy
A
Particles visualized with electron beams, uses magnets to focus. (Used with viruses)
4
Q
Selective permeable barrier
A
Some substances can pass freely through membrane, others cannot, the plasma membrane is..
5
Q
Prokaryotic cells
A
Bacteria
No membrane bound organelles
All material is in one compartment
6
Q
Eukaryotic cells
A
Plant, animal and fungi cells
Has membrane bound organelles
Had nucleus, dna and genome of organism
7
Q
Cell walls
A
Sugar/protein compound (peptidoglycan) outside cell, structural component of cells
8
Q
Plasma membrane
A
Semipermeable phospholipid barrier cells
9
Q
Cytoplasm
A
All substances inside the plasma membrane, major components are water, ions and small molecules
10
Q
Ribosome
A
Cellular machinery used in protein synthesis, located in the cytoplasm
11
Q
Nucleoid
A
Region of cell where chromosome (genetic information of cell) is located
12
Q
Inclusion
A
Storage area of cell (sugars, lipids and phosphates)
13
Q
Photosynthetic membrane
A
Bacteria enclose enzymes and proteins needed in membrane
14
Q
Oxidative phosphorylation
A
Used to produce energy create invaginations of plasma membrane to support process
15
Q
Cytoskeleton
A
Rod shaped bacteria have them
They are helical arrangement of proteins that span the length of he cell, assists with maintenance of cell shape
16
Q
Endomembrane system
A
Used for trafficking, comprised of several organelles
17
Q
Vesicles
A
Bound to membrane used to move compounds between organelles
18
Q
Rough ER
A
Studded with ribosomes, entry point for all membrane trafficking.
19
Q
Smoother ER
A
Has no ribosomes
20
Q
Lysosomes
A
Single membrane enclosed vesicles, contain many digestive enzymes
21
Q
Primary lysosomes
A
Enzymes from the Golgi apparatus are delivered here
22
Q
Secondary lysosomes
A
When phagosome dude with lysosomes
23
Q
Vacuoles
A
Particularly common in plants and fungi
24
Q
Vacuole structure
A
Can occupy up to 90% of plant cell cytoplasm, water filled, responsible for turf or pressure
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Vacuole storage
Compartmentalization of waste and toxins, toxic and distasteful, deters animal consumption for some plants
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Vacuole reproduction
Contain pigments, give color to flowers, attract insects , spreads pollen
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Vacuole catabolism
Enzymes hydrolyze stored seed proteins to monomers, sprouting seeds use for macromolecule production and energy metabolism
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Micro filaments
Composed of actin, 7nm in diameter
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Intermediate filaments
Composed of fibrous protein, 8-12 nm in diameter, critical role in defining cell shape
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Microtubules
Composed of tubular protein, 25 nom in diameter, critical role in defining cell shape
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Flagella
Long and few, 100-200 mm in length
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Cilia
Short and many, covers cell, 0.25 mm in length
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Dynein
Attaches to ruby Lin, ATP dependent motor protein
| Moves in the (+) to (-) direction
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Nexin
Doublets in cilia and flagella crosslinked to prevent sliding
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Kinesin
Molecular motor that attaches to tubulin that moves in the (-) to (+) direction
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Cytoplasmic streaming
Using either molecular motor to move vesicles or organelles in a cell
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Plasmodesmata
Plasma membrane lined channels that are connected.
20-40 nom in diameter.
Transport water ions small molecules proteins hormones and some RNA.
38
Extracellular matrix
Used for cell and tissue integrity in animal cells, has two major components; collagen and proteoglycans
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Collagen
Rope like fibrous proteins, confers rigidity
40
Proyeoglycans
Glycosylated proteins (sugars attached), create help like matrix
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Tight junctions
Form to prevent substances from moving between cells.
Important for organs containing or excluding substances.
Prevents urine from leaking from bladder and prevents fluids from entering lungs.
42
Desmososomes
Connect cells stably, materials in extracellular matrix still move.
Important for conferring flexibility for tissues under stress.
Prevent skin from tearing during movement.
43
Gap junctions
Analogous to plasmodesmata in plants.
Proteinaceous pore connecting cytoplasm of adjacent cells.
Allows exchange of substances between cells.
44
Hydrogen bond
Polar molecules, due to electronegative atom being bound to non-electronegative atom, very weak
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Ionic bonds
Electrostatic interaction between oppositely charged molecules or functional groups, relatively weak
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Hydrophobic interactions
Non-polar molecules or regions of molecules interact to prevent association with aqueous environments
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Covalent bonds
Formed by sharing of electrons to com plays valence shell, very strong; single, double, or triple bonds
48
Deoxyribonucleic acid (DNA)
Responsible for transfer of genetic information.
Harbors coding information for all proteins.
Composed of nucleotides.
49
Ribonucleic acids (RNA)
Transcribes genetic information.
Allows cellular machinery to make proteins.
Composed of nucleotides.
50
Nucleotides have 3 components
1. Phosphate
2. 5 carbon sugars (ribose or deoxyribose)
3. Nitrogenous base
(There are 2; purines and pyrimidines)
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Purines
Adenine and guanine
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Pyrimidines
Cytosine, thymine, and uracil
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Phosphodiester bonds
How nucleotides are assembled into DNA or RNA
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DNA does what to make RNA
Transcription
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RNA does what to make proteins
Translation
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Genes
DNA regions of coding for functional RNA.
| Not all RNA can be transcribed, only the functional ones can
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Homologous genes
Closely related organisms that have similar genes.
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Enzymes
Catalyze reactions to accelerate reaction progress
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Defensive proteins
Include antibodies, respond to foreign substances or invading pathogens.
60
Hormonal regulatory proteins
Control physiological processes, eg. insulin
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Receptor proteins
Receive and respond to signals inside and outside of organism
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Storage proteins
Store monomers (eg. amino acids) for later use
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Transport proteins
Carry substances within organisms (eg. Hemoglobin)
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Genetic regulatory proteins
Regulate gene expression, positive or negative and temporally
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Structure of amino acids
20 different amino acids, basic structure for all the same.
| The only variable is the side chain and there are 3.
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Charged side chain
Carry an electrical charge, hydrophilic with 5 amino acids.
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Polar chain
Has no charge, permanent dipoles due to electronegativity, hydrophilic, has 5 amino acids.
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Aliphatic chain
Non-polar, hydrophobic, has 7 amino acids
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Cysteine
Sulfhydryl group for side chain, technically polar, capable of forming disulfide bond under oxidizing conditions.
70
Glycine
Technically hydrophobic, hydrogen atom for side chain, confers flexibility.
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Proline
Technically hydrophobic, forms covalently closed ring with nitrogen of amine group, limits hydrogen bonding and ability to rotate.
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Peptide linkage
Condensation reaction between amine group of one amino acid and carbonyl group of second amino acid.
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Primary level of protein structure
The order in which the amino acids are joined together
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α-Helix, secondary level of protein structure
Coiled structure, like a slinky or a corkscrew.
Structure formed and maintained by hydrogen bonding.
Hydrogen bonds between amine and carboxyl groups of amino acids in successive turns of coil.
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β-Pleated Sheet, secondary level protein structure
Flat structure, due to polypeptide chain folding back towards itself, draw a board.
Structure also formed and maintained by hydrogen bonding.
Hydrogen bonds between amine and carboxyl groups of amino acids of different regions of chain folded back on its self.
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Tertiary level of protein structures
Occurs when 2 or more α-helixes interact or when 2 or more β-pleated sheets interact.
When any number of a combination of both α-helix and β-pleated sheets interact.
Are held together by: ionic bonds, hydrogen bonds, disulfide bridges, hydrophobic interactions, or Van Der Waals forces.
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Conditions that impact protein structures
Temperature, pH, chaotropic agents, hydrophobic solvents.
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Temperature
Increase disrupts hydrogen bonding, also impacts hydrophobic interactions.
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pH
Decrease or increase impacts ionization of amino acid side chains, can also disrupt hydrogen bonding.
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Chaotropic agents
Tend to be polar, eg. Urea, high concentrations disrupt hydrogen.
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Hydrophobic solvents
Non-polar, denatures most proteins, hydrophobic interactions drives folding of most proteins.
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Energy of activation
Energy required to break existing bonds and begin reaction.
| Can be very high depending on the type of bond that is being broken.
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Catalysts
Enzymes that affect speed of reactions, usually increases rate of reaction.
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Substrates
Reactants in enzymes catalyze reactions
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Active site
Complementary shape to substrate
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Enzyme/substrate complex
Allows binding of substrate
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Apoenzyme
Enzymes that require additional factors for activity.
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Cofactor
An additional factor.
| If inorganic ion, can be a metal ion.
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Coenzyme
Complex organic compound non-covalently bound to active site.
(ATP, biotin, NADH, NADPH)
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Prosthetic group
Complex organic molecule covalently bound to active site.
| Heme, flavin, retinal
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Metabolic pathway
Series of reactions collectively
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Competitive inhibition
Some compounds that can bind enzymes to active site but aren’t used as a substrate.
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Noncompetitive inhibition
Bonding of site by inhibitor prohibits entry of substrates into active site.
Usually due to altered conformation at active site (allostery).
Cannot be competed away by addition of substrate.
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Allosteric site
Sites that bind regulators.
Causes conformational change to proteins.
Can neither activate or inactive enzymes.
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Feedback inhibition
Entire pathways shuts down when sufficient levels of product have accumulated.
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pH
Has an affect on protein structures and functions.
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6 most abundant elements in life
Carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur
Responsible for over 98% of all biomass.
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Protons
(+) chagre
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Neutrons
No charge
100
Electrons
(-) charge
101
Nucleus
Comprised of protons and neutrons with electrons orbiting them.
102
Bohr model
Most space between nucleus and electron orbitals are empty space.
