Test 2 Vocab Flashcards
1
Q
cells
A
fundamental units of life
2
Q
cell theory
A
scientific theory that the cell is the basic unit of life, of which all liveing things are composed, and that all cells are derived from pre-existing cells
3
Q
nucleoid
A
in Prokaryotice cells, not nucleus but the unbound region of DNA
4
Q
cytosol
A
semi fluid substance inside the cell
5
Q
ribosomes
A
complexes that make proteins according to instructions from the genes
6
Q
lysosomes
A
digestive organelles where macromolecules are hydrolyzed
7
Q
centrioles
A
centrioles microtubules are activated here and help with cell division
8
Q
flagella
A
a long, whiplike structure extending from certain cells and used in locomotion (present in some plant sperm)
9
Q
chloroplast
A
photosynthetic organelle, converts energy of sunlight to chemical energy stored in sugar molecules
10
Q
central vacuole
A
functions to storage, breakdown of waste, plant growth, and hydrolisis of macromolecules
11
Q
cell wall
A
composed of cellulose, helps maintain cell shape and provides protection, and helps prevent excess water uptake (bacteria, fungi, and plant cells have cell walls)
12
Q
plasmodesmata
A
(“plasma binded”) cytoplasmic channels through cell walls that connect the cytoplasms of adjacent cells
13
Q
plasma (cell) membrane
A
functions: selectively permeable, physical barrier, communication , structural support; amphipathic; and also contains proteins, cholesterol, glycoproteins and glycolipids
14
Q
amphipathic
A
both hydrophilic (water loving) and hydrophobic (water fearing)
15
Q
cytoplasm
A
the material between the nucleus and plasma membrane of the cell
16
Q
organelles
A
metabolic machinery of the cell; “little organs” that preform functions for the cell
17
Q
inclusions
A
not in all cell cytoplasm; chemical substances such as stored nutrients or cell products; e.g. lipid droplets common in fats cells, melanin pigment in skin and hair cells
18
Q
nucleus
A
membrane bound organelle located near the center of most cells; functions as the control center of the cell (contains genetic material (DNA), gives/receives info regarding all cellular processes, and site of DNA and RNA synthesis
19
Q
nucleolus
A
nucleus contains one or more nucleoli; sites of ribosomes assembly and rRNA synthesis
20
Q
chromatin
A
composed of DNA and protein; present when the cell is not dividing; scattered throughout the nucleus; condenses to form chromosomes when the cell divides
21
Q
mitochondria
A
(“powerhouse” of the cell) double membrane bound organelle that produces ATP; site of aerobic respirations (carbohydrates and oxygen converted to ATP energy and carbon dioxide); contains two different compartments, both are part of the inner mitochondrial membrane (matrix and cristae: sites of ATP synthesis)
22
Q
endoplasmic reticulum (ER)
A
the cell’s “factory”; fluid-filled tubules for carrying substances; manufactures, packages, and distributes in transport vesicles; part of the endomembrane system
23
Q
endomembrane system
A
which include the nuclear envelope, ER, Golgi apparatus, lysosomes, vesicles and vacuoles; this system regulates protein traffic and performs metabolic functions in the cell
24
Q
rough endoplasmic reticulum (RER)
A
studded with ribosomes which synthesize proteins and dump into RER lumen (space) for further processing
25
ribosomes
made of protein and rRNA; sites of protein synthesis-read mRNA and assemble proteins; found at two locations: free in the cytoplasm and as part of the RER
26
smooth endoplasmic reticulum (SER)
makes lipids (phospholipids, fatty acids, and steroids) and carbohydrates
27
smooth endoplasmic reticulum (SER)
makes lipids (phospholipids, fatty acids, and steroids) and carbohydrates; contains enzymes that detoxify chemicals; storage of calcium ions in muscle cells
28
golgi apparatus
the "UPS" of the cell; contains stacks of flattened, membranous sacs called cisternae; receives molecules from the ER and processes, sorts, modifies packages, and ships them; produces different types of packages: secretory vesicles, cell membrane components, and lysosomes
29
lysosomes
the cell's "garbage disposal"; synthesized in the golgi apparatus and bud from the Golgi; contain enzymes produced by ribosomes; digest nutrients, bacteria, damaged organelles, ect.
30
perosisomes
membranous sacs of enzymes, break down free radicals (highly reactive chemicals with unpaired electrons) that are produced from the metabolism of lipids (convert to hydrogen peroxide then convert to water by catalose); detoxify harmful substances such as alcohol and formaldehyde
31
vacuoles
storage "sacs"; large, fluid-filled enclosed membrane derived from ER and Golgi apparatus; types: food, central, and contractile
32
cytoskeleton
network of protein structures that extend throughout the cytoplasm giving mechanical strength, shape and flexibility; three different types of elements: microfilaments (smallest), intermediate filaments (internal wires to help resist pulling forces on the cell), microtubles (largest, hallow tubes made of globular protein tubilin that determind the overall shape)
33
microvilli
tiny, fingerlike extensions of the plasma membrane with a core of actine microfilaments; increase surface area for absorption; found on intestinal and kidney tubule cells
34
cilia
numerous, short hair-like projections made of microtubules; move material across the cell surgace thus commonly associated with goblet cells; located in the respiratory bronchi and uterine tubes, on the protist paramecium
35
flagella
long, whip-like structure made of microtubules; propels the cell; found on sperm
36
selective permeability
allows some substances to cross more easily than others
37
fluid mosaic (collage)
phospholipids and some proteins move laterally; as temperature cool, membranes switch from a fluid state to a solid state (depends on the types of lipids, unsaturated versus saturated fatty acid); steroid cholesterol within the animal cell membrane (at warm temps, cholesterol restains movement where cool temps prevents tight packing)
38
peripheral proteins
bound to the surface, not embedded in the lipid bilayer
39
integral proteins
penetrate the hydrophobic core; hydrophobic regions consist of one or more stretches of nonpolar amino acids; majority of integral proteins are transmembrane proteins that span the membrane
40
transport proteins
allow passage of hydrophilic substances; transport protein is specific for the substances it moves
41
channel proteins
have a hydrophilic channel that certain molecules or ions can use as a tunnel
42
aquaporins
protein channels that facilitate the passage of water
43
carrier proteins
bind to molecules, change shape to shuttle them
44
solution
homogeneous mixture of two or more components
45
solvent
dissolving medium; typically water in an organism, substance present in large ammount in a solutions
46
solute
what is being dissolved, substance present in small amount
47
passive transport
substances are moved down their concentration gradient across the membrane without any energy input from the cell
48
concentration gradient
a region along which the density of a chemical substance increases or decreases; substances move "downhill" with the gradient from high concentration (more molecules of solute) to low concentrations (less molecules of solute)
49
simple diffusion
the unassisted movement of solutes across the cell membrane from high to low concentration (goal is dynamic equilibrium)
50
facilitated diffusion
passive transport aided by proteins; carrier proteins and channel proteins
51
osmosis
the diffusion of water across a selectively permeable membrane; water diffuses across the membrane from the region of lower solute concentration to that of higher solute concentration until solute concentrations on both sides of membrane are equal
52
osmotic pressure
the tendency of a solution to pullwater into it (is directly related to the concentration of solutes in the solutions); the higher the solute concentration the greater the osmotic pressure and the greater the tendency of water to move into the solution
53
Tonicity
ability of a surrounding solution to cause a cell to gain or lose water
54
Hypotonic
less solute; Net movement of water from hypotonic
| environment to hypertonic environment
55
Isotonic
equal solute; No NET movement of water across the plasma membrane
56
Hypertonic
more solute; Net movement of water from hypotonic
| environment to hypertonic environment
57
bioenergetics
study of how enegy flows through living systems
58
energy
capacity to do work
59
work
to move matter against opposing forces
60
kinetic energy
energy of motion; heat/thermarl energy-KE associated with the radom movement of atoms and molecules
61
potential energy
energy of position, stored energy; chemical energy-PE of a chemical bond
62
thermodynamics
study of energy and its transformations
63
systems
the matter under study
64
surrounding
everything outside the system (the rest of the universe)
65
open systems
exchanges energy with the environment; eg biological systems
66
isolated/closed systems
no exchange of energy with the environment; eg thermos
67
first law of thermodynamics
energy of the universe is constant. energy connot be created or destroyed, only transformed. aka the law of conseration of energy
68
second law of thermodynamics
every energy transfer or transformation increases the entropy of the universe
69
entropy
measure of disorder or randomness
70
spontaneous processes
a process that can occur without energy input; "energetically favorable" process; does NOT imply process would occur quickly; eg diffusion
71
metabolism
the sum of all chemical reactions that enable an organism to carry out its activities
72
metabolic pathway
a specific molecule altered through a series of steps resulting in a product; each step is catalyzed by a specific enzyme; membranes help organize these reactions
73
catabolic reation (catabolism)
larger molecules are broken down to smaller molecules; break bonds
74
anabolic reactions (anabolism)
reactions where larger molecules are synthesized from smaller molecules; make bonds
75
free energy (ΔG)
energy free to do "useful" work when temperature and pressure are uniform, as in a living cell
76
entropy (ΔS)
change in a system's entropy
77
enthalpy (ΔH)
the total chemical potential energy of a system
78
exergonic reactions
downhill, spontaneous, hydrolysis; reaction in which the bonds in the products have less free than the bonds in the reactants; releases energy (lower free energy) and is spontaneous; example: diffusion, cell respiration, catabolism; ΔG is negative (reactants have more free energy than the products)
79
endergonic reaction
uphill, dehydrations, nonspontaneous ; reaction in which the bonds in the products have more free energy than the reactants; nonspontaneous, need an input of energy to get them going (free energy increases); example: photosynthesis, anabolism; ΔG is positive (reactants have less free energy)
80
chemical work
type of work that cells do; example:endergonic reaction, require free energy, eg synthesis of polymers from monomers
81
transport work
type of work that cells do; pumping of substance against a concentration gradient
82
mechanical work
type of work that cells do; beating of cilia, muscle contraction, movement of DNA
83
energy coupling
use exergonic process to drive an endergonic; usually mediated by ATP
84
ATP (adenosine triphosphate)
chemical compound (nucleotide) that packages energy; composed of ribose (a sugar), adenine (a nitrogenous base), and three phosphate groups
85
enymes
ASE; biological catalysts; speeds up the rates of chemical reactions by lowering the activation energy; organic catalysts generally made of protein
86
catalyst
a chemical agent that speeds up a reaction without being consumed by the reaction
87
activation energy (Ea)
initial energy needed to start chemical reaction
88
substrate
the reactant an enzyme acts on; combination of enzyme + substrate is called enzyme-substrate complex
89
active site
region on enzyme where a substrate binds; *test*: active site can lower an Ea barrier by-orientating substrates correctly, straining substrates bonds, providing a favorable microenvironment, covalently bonding to the substrate
90
induced fit
enzyme changes shape slightly when it binds the substrate; brings chemical groups of the active site into positions that enhance their ability to catalyze the reaction
91
optimum temperature
temperature at which the enzyme works best and has the greatest turnover rate; different cells or organisms may have enzymes with different optimum temperatures
92
optimum pH
the pH at which the enzyme works best; proteins are held together by ionic interactions that are affected by changing the pH of the solution that surrounds them; different enzymes have different
93
cofactors
non-protein molecules (eg metal atoms) necessary for enzyme function
94
coenzymes
a non-protein organic cofactors (eg vitamins)
95
inhibitor
substances which reduce the effectiveness of enzymes
96
reversible inhibition
inhibitor forms weak chemical bonds with enzyme thus can restore function
97
competitive inhibition
inhibitor competes with normal substrate for binding to active site
98
noncompetitive inhibition
inhibitor binds to sites other than active sites
99
irreversible inhibition
permanent inactivation of enzymes through forming stable bonds or denaturation; example mercury and led
100
denaturation
changing proteins native shape
101
allosteric regulation of enzymes
any case in which a protein's function at one site is affected by the binding of a regulatory molecule to a separate site
102
cooperativity regulation of enzymes
binding of one substrate molecule primes binding or activity at other active sites
103
enzyme pathways (cascades)
the product of one enzyme will affect activity of another
104
negative feedback inhibition
the end product of a metabolic pathway allosterically inhibits the enzyme for a previous step in the pathway
105
Catabolism
Breakdown of larger molecules
106
Fermentation
A partial breakdown of sugars that occurs without O2
107
Aerobic respiration
Complete breakdown of sugars in the presence of O2
108
Cellular respiration
Includes both aerobic and anaerobic respiration
109
Redox reaction
Aka oxidation reduction reaction; chemical reactions that transfer electrons between reactants; LEO goes GER (loose electron oxidation and gain electron reduction)
110
Oxidation
A substance loses electrons or is oxidized
111
Reduction
A substance gains electrons or is reduced (the amount of positive charge is reduced)
112
Reducing agent
Electron donor
113
Oxidizing agent
Electron acceptor
114
Dehydrogenase
An enzyme that removes a pair of hydrogen Atoms
115
Glycolysis
Glucose——>two pyruvate (3-C); harvests chemical energy by oxidizing glucose to pyruvate
116
Formation of acetyl-coenzyme A
Pyruvate—-> acetyl-CoA
117
Citric acid (Krebs Cycle)
Acetyl-CoA—>electron carriers, completes the breakdown of glucose to CO2
118
Oxidative phosphorylation
Production of ATP using energy derived from the redox reactions of an electron transport chain
119
Preparatory phase (energy investment phase)
Energy consumed; glucose is stable, an investment of ATP is needed to get the reaction going
120
Phosphorylation
A phosphate group is transferred from ATP to glucose, the bond of glucose break and it is rearranged through. Series of 3 steps
121
Dehydrogenation
G3P is oxidized by enzymes dehydrogenase to reduce NAD+
122
Decarboxylation
The removal of CO2 from a molecule
123
Electron transport chain (ETC)
Chain of proteins and other molecules; it is located in the inner membrane (cristales) of the mitochondrion (in eukaryotes); locates in the plasma membrane of prokaryotes
124
Proton-motive forcé
H+ gradient (created by ETC) across the membrane
125
Chemiosmosis
Use of energy in a H+ gradient to drive cellular work
126
ATP synthase
A special protein that H+ moves back across the membrane down their concentration gradient through
127
Anaerobic respiration
Uses an ETC with a final electron acceptor other than O2
128
Fermentation
Incomplete break down of glucose
129
Alcohol fermentation
Pyruvate is reduced by NADH, releasing CO2 forming ethanol
130
Lactic acidosis fermentation
Pyruvate is released by NADH, forming lactate as an end product; no release of CO2
