Unit 3 Flashcards
Cellular Engernetics
1
Q
kinetic energy
A
movement
2
Q
heat energy
A
temperature
3
Q
chemical energy
A
- potential energy
- how biological systems store energy
4
Q
metabolism
A
manages the material and energy resources of the cell
5
Q
catabolic pathway
A
leads to the release of energy by the breakdown of complex molecules to simpler compounds
- ex. fermentation and aerobic respiration
6
Q
aerobic respiration
A
- energy from biological macromolecules is used to produce ATP
- ex. cellular respiration
7
Q
anabolic pathway
A
consumes energy to build complicated molecules from simpler ones
8
Q
thermodynamics
A
the study of energy transformations that occur in matter
9
Q
1st law of thermodynamics
A
conservation of energy
10
Q
2nd law of thermodynamics
A
- entropy (ΔS) is always increasing, no matter what
- potential energy final state > potential energy initial state
- energy cannot be recycled
- living things must have a constant inflow of energy
11
Q
entropy
A
- ΔS
- the disorder of the universe
12
Q
Gibbs free energy
A
- ΔG
- the part of a system’s energy that is able to perform work when temperature is uniform
13
Q
endergonic reaction
A
- positive ΔG/free energy
- reaction increases ability to do work by absorbing free energy/ΔG
- NOT spontaneous
14
Q
exergonic reaction
A
- negative ΔG/free energy
- reaction spends energy on work, doesn’t require more to take place
- spontaneous
- ex. cellular respiration
15
Q
enthalpy
A
- ΔH
- total potential energy
16
Q
positive ΔH/enthalpy
A
- reaction causes the gain of potential energy from the environment
- endergonic reaction
17
Q
negative ΔH/enthalpy
A
- reaction results in the loss/release of energy into the environment
- exergonic reaction
18
Q
fundamental equation of thermodynamics
A
ΔG = ΔH - (time)(ΔS)
19
Q
ATP
A
- adenosine triphosphate
- adenine, ribose, chain of three phosphates
- bonds between phosphates are extremely energetic and release a lot of energy when broken
- hydrolysis results in adenosine diphosphate (ADP)
20
Q
reaction coupling
A
- takes an exergonic reaction and couples it with an endergonic reaction
- the use of a reaction that releases energy to drive a reaction that requires energy to take place
21
Q
enzyme
A
- biological catalyst
- speeds up reaction selectively and without being consumed
- lowers the activation energy (Ea) of a reaction but does not alter the free-energy change of the reaction
- has optimal pH and temperature by which it operates best in (increased temp. = more collisions, but too hot denatures it)
22
Q
enzyme-substrate complex
A
slight positive charge of substrate should match the slight negative charge of enzyme
23
Q
competitive inhibition
A
where a molecule blocks (competes for) the active site of an enzyme
- ex. many poisons
24
Q
non-competitive inhibition
A
where a molecule attaches somewhere else on the enzyme than the active site (no direct competition)
- called the allosteric site
- can make enzyme do more or less by changing its shape
25
feedback inhibition
- takes place when enzyme product isn't needed as much anymore
- enzymes don't just disappear when its done producing for a cell in need
26
activation energy (Ea)
the amount of energy it takes to break the bonds of the reactant molecules in a reaction
27
cofactor
- nonprotein enzyme helper
- metal ions
- function in a way crucial to allowing catalysts to occur
28
coenzyme
biological cofactor
- ex. vitamins
- ex. NAD+, FAD
29
CELLULAR RESPIRATION
- uses oxygen to break down glucose in order to get energy (ATP)
- also releases water and carbon dioxide, like when an animal breathes in and out and pees/sweats
- reactions termed oxidative-reduction reactions
30
oxidation
loss of electrons from reactants
31
reduction
gain of electrons from reactants
32
cellular respiration generally takes place within the ______
mitochondria
33
cellular respiration equation
C6H12O6 + 6O2 -> 6CO2 + 6H2O
1. glycolysis {6C glucose -> two 3C pyruvate, 2 ATP, 2 NADH}
1.5. pyruvate oxidation {2 pyruvate -> two 2C acetyl coA, 2 CO2, 2 NADH}
2. krebs/citric acid cycle {2 acetyl coA -> completely broken down glucose, 4 CO2, ATP, 3 NADH, FADH}
3. electron transport chain {H+ extraction from electrons carried by NADG}
34
glycolysis
- shared by all life forms and does not require O2
- oxidizes glucose to harvest chemical energy in the form of 2 pyruvate (3C), 2 ATP, and 2 NADH (per turn)
35
citric acid/krebs cycle
takes what's left over (pyruvate 3C) and extracts all of its energy
- pyruvate transferred by a transport protein from the cytosol into the matrix of the mitochondria
- oxidized to acetyl coA
- each turn requires 1 acetyl coA to produce 2 CO2, 3 NADH, 1 FADH2, 1 ATP
36
electron transport chain
converts all types of energy into ATP
37
electrochemical gradient
- used in photosynthesis and cellular respiration and by prokaryotes
- stores potential energy by a diffusion gradient and an electric charge gradient across a membrane
38
chemiosmosis
- a.k.a. oxidative phosphorylation
- H+ molecules allowed back into cell after being pushed out repeatedly to produce more ATP from ADP
- energy-coupling mechanism
- used by both chloroplasts and mitochondria to generate ATP
39
fermentation
- does NOT use O2
- breaks down glucose again and again to produce 2 ATP and 2 NADH each time
- converts NADH to NAD+ to use it again
40
alcohol fermentation
pyruvate is converted to ethanol, releasing CO2 and oxidizing NADH to create more NAD+
41
lactic acid fermentation
pyruvate is reduced by NADH and lactate is formed as a waste product
42
phosphofructokinase (PFK)
an allosteric enzyme that functions early in glycolysis and acts as a respiration regulator
- inhibited by high levels of ATP, which slows glycolysis
- when ATP is needed in higher concentrations, a product of ADP acts as an allosteric activator on PFK and increasing ATP production
43
autotrophs
make their own food using photosynthesis
- the producers
44
heterotrophs
live on compounds produced by other organisms
- the consumers
45
the exterior of the lower epidermis of a leaf contains many pores called _____, through which carbon dioxide enters and oxygen and water vapor exit the leaf
stomata
46
transpiration
the loss of water through open stomata
47
PHOTOSYNTHESIS
- taking energy from light and storing it in glucose
- light dependent reaction
48
photosynthesis equation
CO2 + H20 -> C6H12O6 + O2
1. light reactions
2. calvin cycle
49
light reactions
1. chlorophyll absorbs light energy, which drives the transfer of electrons from H2O to NADP+, forming NADPH
- when the electrons are "eaten up"- this takes place at photosystem II
2. ATP is generated and continued using chemiosmosis
- generated by pumping out protons
50
calvin cycle pt. 1
- mostly only happens during the day
1. occurs in stomata, CO2 from air incorporated through carbon fixation
51
Calvin cycle pt. 2
2. three CO2 molecules attach to 3 molecules of 5C sugar ribulose biphosphate (RuBP), catalyzed by enzyme rubisco, to produce two 3-phosphoglycerate. Carbon has been fixed (into an organic compound)
52
Calvin cycle pt. 3
3. the 3-phosphoglycerates are phosphorylated to become six 1,3-bisphosphoglycerates
53
Calvin cycle pt. 4
4. NADPH (6) reduce six 1,3-bisphosphoglycerates into six glyceraldehyde 3-phosphates (G3P), one to be used by the plant cell
54
Calvin cycle pt. 5
5. remaining G3P rearranged to generate 3 RuBP molecules
55
two G3P's make one ______ molecule
glucose
56
photorespiration
using O2 instead of CO2 to accommodate for changes in environment (temperature, etc.)
57
C3 plants are the "______" plants
normal
- keep stomata closed to conserve water, so no CO2 intake
- rubisco can bind to O2 instead of CO2, causing the breakdown of RuBP, resulting in loss of energy and carbon (photorespiration)
58
C4 plants use _____ to fix CO2
PEP carboxylates
- enzyme that C3 plants don't have
-acts as CO2 for cells specializing in the Calvin cycle
- limit photorespiration
59
Crassulacean Acid Metabolism (CAM)
only open stomata at night, CO2 is fixed in organic acids and stored in vacuoles to be released in the morning
60
light is _______ energy that travels in ______ waves
electromagnetic energy; rhythmic waves
- visible spectrum is the portion we can see (ROYGBIV)
- behaves as though it is made up by discrete particles called photons
61
pigments
substances that absorb light
62
chlorophyll is a pigment that absorbs ______ and _____ light
violet-blue; red
63
absorption spectrum
a graph plotting a pigment's light absorption as a function of wavelength
64
action spectrum
graphs the effectiveness of different wavelengths of light in driving the process of photosynthesis
65
photosystems
two parts:
1. light-harvesting complex
2. reaction center
66
light-harvesting complex
made up of many chlorophyll and carotenoid molecules that donate electrons to the primary electron acceptor, which converts light to chemical energy
67
reaction center
- energy from the light harvesting complex transferred here
consists of two chlorophyll a molecules that donate electrons to the primary electron acceptor, which converts light to chemical energy
- splitting of water replaces donated electrons
68
photosystem I
- a.k.a. P700
- found first, second in line on electron transport chain
69
photosystem II
- a.k.a. P680
- found second, first in line on electron transport chain
70
