Test 2 Flashcards
1
Q
What are the two basic forms of energy?
A
Potential energy and kinetic energy
2
Q
What is potential energy?
A
stored energy
3
Q
What is kinetic energy?
A
energy in the process of doing work
4
Q
What determines how much potential energy is stored in a system?
A
- the function of order
- the more order the system, the more potential energy
5
Q
Which side has more order / more potential energy?
AB –> A + B
A
- the reactants have more order so more potential energy
- reactants are less stable
6
Q
Exothermic / Exergonic reaction
A
- reduction in potential energy
7
Q
Activation energy
A
energy required to start a reaction
8
Q
2 ways to overcome activation energy
A
- Heat (energy)
- Catalyst/Enzymes
9
Q
What is an active site?
A
region of an enzyme where a substrate binds and undergoes a chemical reaction
10
Q
What is a cofactor?
A
an inorganic substance that binds to an enzyme and activates an active site
(only required for certain enzymes)
11
Q
What is a coenzyme?
A
an organic molecule that binds to an enzyme and activates an active site
(required for all enzymatic activity)
12
Q
Endothermic/Endergonic Reaction
A
- increase in potential energy
- driven by/ requires exergonic reactions
- requires energy and enzyme
13
Q
What supplies the neccesary energy to drive all of the endergonic processes of the cell?
A
Cellular respiration
14
Q
Cellular Respiration (aerobic)
A
a series of exergonic reactions that break down organic molecules to release their energy and harnessing that energy to create adenosine triphosphate (ATP)
15
Q
What is ATP (adenosine triphosphate)?
A
an energy carrier
16
Q
What are the 4 processes of cellular respiration?
A
- Glycolysis
- Pyruvate oxidation
- Kreb’s cycle
- Oxidative Phosphorylation
17
Q
Glycolysis
A
- breaking down a sugar
Occurs: in cytoplasm
Reactants: glucose, 2 ADP, 2 Pi (inorganic phosphate), 2 NAD+
Products: 2 ATP, 2 NADH, 2 Pyruvate
Overall Picture: coupling of endergonic and exergonic rxns to create ATP
18
Q
What is the transfer of electrons called?
A
Oxidation and Reduction
19
Q
Pyruvate Oxidation
A
Occurs: mitochondrial matrix
Reactants: 2 pyruvate, 2NAD+, 2 CoenzymeA
Products: 2 CO2, 2NADH, 2 AcetylCoA
Overall Picture: coupling of endergonic and exergonic rxns to create ATP
20
Q
Citric Acid Cycle / Kreb’s Cycle
A
Occurs: in matrix
Reactants: 2 AcetylCoA, 2 FAD+, 6 NAD+, 2 ADP, 2 Pi
Product: 2 FADH2, 6 NADH, 2 ATP, 4 CO2
Overall picture: coupling of endergonic and exergonic rxns to create ATP
21
Q
What is FADH2?
A
A high energy electron carrier
22
Q
How many CO2 molecules are produced from cellular respiration?
A
6 CO2 molecules
23
Q
How many H2O molecules are produced from cellular respiration?
A
6 H2O molecules
24
Q
Step 1 of oxidative phosphorylation
A
- Generate a proton motive force
- high energy electrons from NADH and FADH2 are passed down an electron transport channel to a low energy state (EXERGONIC; HIGH TO LOW ENERGY) DOWN CONCENTRATION GRADIENT
- energy that is released is used to pump H+ across a membrane to produce a [H+] gradient = proton motive force (ENDERGONIC; ACTIVE TRANSPORT) UP CONCENTRATION GRADIENT
25
Step 2 of oxidative phosphorylation
- Chemiosmosis
- use the proton motive force to phosphorylate ADP to make ATP
26
What is oxidized and reduced in oxidative phosphorylation?
Oxidized: NADH and FADH2
Reduced: O2
27
Oxidative Phosphorylation
FOR ONE GLUCOSE MOLECULE
Occurs: on inner membrane of mitochondria
Reactants: 10 NADH, 2 FADH2, O2, ADP, 2 ATP
Products: 38 ATP, NAD+, FAD+, 6H2O
28
What is the theoretical max number of ATP molecules created in cellular respiration?
36 ATP per glucose molecule
29
How many ATP molecules does NADH produce?
3 ATP
30
How many ATP molecules does FADH2 produce?
2 ATP
31
Anaerobic Respiration
Bacteria use non-oxygen (SO4) final electron receptor in oxidative phosphorylation
32
What is the final electron receptor in oxidative phosphorylation?
oxygen
33
What is fermentation?
using glycolysis to produce ATP
34
Lactic Acid Fermentation
- supplement to aerobic respiration
glucose , 2 NAD+ , 2 ADP, 2 Pi
--> glycolysis
2 lactic acid, 2 NAD+, 2 ATP
35
When and why does our body undergo lactic acid fermentation?
- during times of strenuous exercise
- respiratory and cardiovascular systems cannot transport O2 to muscle cells fast enough
- denatures proteins and causes soreness
36
Alcoholic Fermentation
glucose , 2 NAD+ , 2 ADP, 2 Pi
--> glycolysis
2 NAD+, 2 ATP, 2 ethanol, CO2
37
What is NADH?
A high energy electron carrier
38
Lipid Metabolism
- Triglyceride is hydrolysized (3 H2O)
- breaks triglyceride into 3 long chain fatty acids + glycerol
- fatty acid chain breaks off 2 carbons at a time and bonds reacts with coenzyme A to make AcetylCoA which then goes into the C.A.C
- glycerol is metabolized into pyruvate which then undergoes Pyruvate oxidation
39
Protein Metabolism
- Protein is hydrolysized into amino acids
- Amino acids go on to make more proteins
- An excess of amino acids get used as energy
- Amino acid undergoes deamination (removal of amino group) with H2O and produces NH3 and carbo skeleton
- Carbon skeleton group goes into the citric acid cycle (has 20 pathways)
40
How do fish, some amphibians, and aquatic insects remove nitrogenous waste?
they diffuse NH3 across gill surface
41
How do mammals and some amphibians remove nitrogenous waste?
- convert NH3 to urea (liver does this)
- urea is non-toxic and soluble in water (makes it safe for the body to transport without damaging cells)
- urine
42
How do reptiles, birds, and terrestrial insects remove nitrogenous waste?
- NH3 --> urea --> uric acid (pasty solid)
43
Glucose vs Lipids as sources of energy
Glucose:
- small
- polar (easily transported in water based solution; blood)
- 4 kcal/g
Lipids:
- large
non-polar (not easily transported, clumps)
- 9 kcal/g
44
Regulation of Metabolic Processes (2 Mechanisms)
1. Equilibrium Dynamics
2. Feedback inhibition
45
Equilibrium Dynamics
The rate of the forward reactions is equivalent to the rate of the reverse reaction
46
Feedback Inhibition
At a high concentration, a reaction product binds to and inhibits the enzyme that catalyses the reaction
47
What happens if there is an excess of ATP caused by eating too much and not using. the ATP that is produced?
- results in a build up of pyruvate and AcetylCoA that gets transformed into glycerol and fatty acids to make fat
- high blood sugar levels, increase in glycogen in liver
48
If 38 ATP is made from one glucose molecule, why is 36 ATP the theoretical max?
2 ATP is used to transport the 2 NADH from the cytoplasm into the mitochondria
49
What is photosynthesis?
the capture of light energy and the use of that energy to generate organic molecules
50
What are the 2 major photosynthesis processes?
- Light dependent rxns (LDR)
- Light independent rxns
51
Light dependent rxns
- light energy is captured by photosynthetic pigment and used to generate ATP and NADPH
- occurs on membranes (thylakoid membrane and membrane folds of prokaryotes)
- contains photosystems
- 2 versions:
a. cyclic photophosphorylation
2. non-cyclic photophosphorylation
52
Who undergoes photosynthesis?
- plants
- algae
- photosynthetic bacteria
- cyanobacteria
53
What is light?
electromagnetic energy that travels in the form of waves
- wavelength ranges from 400nm-740nm (visible light)
54
What is wavelength?
1/frequency
55
How do we experience infrared light?
through heat
56
Photon
- packet of light energy
- no physical mass
- to be used, it must strike an electron in photosynthetic pigment molecule (2 outcomes)
57
What are the two outcomes when a photon strikes an electron in photosynthetic pigment molecule?
1. light will be reflected if electron frequency is not equal to the photon frequency
2. light will be absorbed if electron frequency is = photon frequency
58
What happens when light is absorbed by an electron?
- the energy from the photon is transferred to the electron
- photon no longer exists
- electrons become high energy electrons (needed for oxidative phosphorylation)
59
What light is reflected in photosynthesis?
Green light
60
Photosynthetic pigments
- pigment used to capture light and convert it into chemical energy
- each pigment has their own absorption spectrum
61
What is absorption spectrum?
the wavelength of light that a photosynthetic pigment absorbs
62
What is action spectrum?
the wavelengths of light used by the photosynthesizer
63
Chlorophyll (Bacterial)
- A.S. = 870 nm
64
Chlorophyll A
- all eukaryotes and cyanobacteria
- A.S. peaks at 420 nm and 660 nm
65
What is a photosystem?
A cluster of photosynthetic pigments in a TMP
66
What does the reaction center chlorophyll (RCC) do?
generates high energy electrons
67
What makes up the antenna complex and what does it do?
- photosynthetic pigment molecules make up the antenna complex
- captures light energy and transports to RCC
68
Cyclic Photophosphorylation
- photosynthetic bacteria
1. light strikes antenna complex on P870
2. energy absorbed is transferred to RCC
3. RCC generates 1 high energy electron
4. high energy is passed to ETC (high energy state to low energy state; active transport)
5. electron is passed back to P870
6. energy released is used to create proton motive force
7. energy released from proton motive force is used to generate ATP
69
Non-Cyclic Phosphorylation
- eukaryotic and cyanobacteria
- thylakoid membrane
1. light strikes P680 and 2 high energy electrons are passed to ETC
2. ETC passes 2 high energy electrons to low energy state (P700)
3. light strikes P700 and 2 high energy electrons are passed to NADP reductase
4. energy released is used to create proton motive force
5. creates O2, NADPH, and ATP
70
What is NADP reductase?
- reduces NADP+ to create NADPH
- the 2 high energy electrons and H+ bind to NADP+
71
What is the great oxidation event?
- oxygen levels in the environment arose
- 3.7 BYA first fossil evidence of life
- 3.3 BYA first fossil evidence of cyanobacteria
2.7 BYA first eukaryotes
- cyanobacteria led to the rise in oxygen levels which led to eukaryotes
72
Light Independent Rxn
- AKA calvin cycle
- occurs in stroma
- carbon fixation
73
What is carbon fixation?
the conversion of inorganic carbon to organic carbon
74
Chemical Rxn for Light Independent Rxn
6CO2 + 12NADPH + 18ATP --> C6H12O6 + 12 NADP+ + 18 ADP + 18 Pi
75
Calvin Cycle
- occurs in stroma
- 1 carbon fixed for each turn of the cycle
- 6 cycles to form 1 glucose molecule
76
What is rubisco?
an enzyme that fixes carbon
77
Where is the glucose made and what is a biproduct
- occurs in the cytoplasm
-2 Pi is a by product
- glucose that is made goes on to become starch, goes through cellular respiration, or turned into cellulose
78
Calvin Cycle Rxn
1. 6CO2 + RuBP + Rubisco
2. 12PGA (IS REDUCED) + 12NADPH + 12ATP
3. 12G3P + 12NADP+ + 12ADP + 12Pi
4. 2G3P goes to cytoplasm; 10G3P regenerates into RuBP by using 6 ATP, creating 6ADP + 4Pi (2Pi gets regenerated into RuBP)
