BIO CH 3 Flashcards
1
Q
catabolism
A
break down macromolecules and release ATP
2
Q
Anabolic
A
use ATP to build macromolecules
3
Q
Chemical energy
A
a form of potential energy where chemical bonds serve as a store of energy and have the potential to be used to do work
4
Q
exergonic reactions
A
release energy, are spontaneous reactions (negative Gibbs free energy)
-EXergonic reactions means that free energy is EXiting the system
5
Q
endergonic reactions
A
require energy, are non-spontaneous processes because they require energy input to proceed to final state
6
Q
What is ATP
A
energy source
is an RNA nucleotide/RNA nucleoside triphosphate
7
Q
difference between RNA and DNA
A
RNA- ribose sugar (OH on 2’)
DNA- Deoxyribose sugar (H on 2’)
8
Q
Component of ATP
A
- adenosine
- ribose sugar
- 3 phosphate groups
9
Q
Difference between ATP and RNA nucleic acid
A
RNA has 1 phosphate, ATP has 3 phosphate groups
10
Q
___ reactions breaks the high potential energy bonds of phosphate to release free energy
A
hydrolysis
11
Q
What is reaction coupling
A
powering an energy-requiring reaction with an energy-releasing one, resulting in a negative Gibbs free energy (exergonic)
12
Q
Mitochondria make ATP through ____, which is a _____process
A
cellular respiration
catabolic
13
Q
The intermembrane space of mitochondria is
A
acidic
14
Q
Mitochondrial matrix contains its own
A
circular DNA and ribosomes
15
Q
Chloroplasts contains its own
A
circular DNA and ribosomes
16
Q
What is the endosymbiotic theory
A
mitochondria(aerobic) and chloroplasts(photosynthetic) were once free-living bacteria, then internalized.
17
Q
Aerobic cellular respiration is a ___ pathway that requires ____
A
catabolic
oxygen
18
Q
Glycolysis converts ___ into ____ and is an ____ process
A
glucose
pyruvate
anaerobic
19
Q
Where does glycolysis take place
A
cytosol
20
Q
During glycolysis, NAD+ is ___ to NADH
A
reduced
21
Q
What are the two phases of glycolysis
A
energy investment phase
energy payoff phase
22
Q
Where is glucose phosphorylated by in the cytosol
A
glucokinase and hexokinase (only have to know hexokinase for the DAT though)
23
Q
phosphorylation is
A
non-reversible
24
Q
What is glucose called after phosphorylation?
A
glucose-6-phosphate
25
What is an isomerase
an enzyme that modifies glucose-6-phosphate into fructose-6-phosphate
26
What steps of glycolysis hydrolyze ATP?
Glucose-> Glucose-6-phosphate
| Fructose-6-phosphate-> fructose-1,6-bisphosphate
27
What enzymes phosphorylates fructose-6-phosphate?
phosphofructokinase (PFK), makes fructose-1,6-bisphosphate
28
What are the irreversible steps of glycolysis?
those that require the hydrolysis of ATP
29
PFK is an
essential regulatory enzyme
30
By the end of the energy investment stage, ____ and ____ are made and exist in equilibrium
glyceraldehyde-3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP)
31
G3P and DHAP are ___-carbon sugars
3
32
Which of the sugars undergoes additional reactions in glycolysis
G3P
33
What is produced during the energy-payoff phase?
```
4 ATP (Net gain: 2), 2 pyruvate, 2 NADH
(total- for each G3P- 2 ATP, 1 pyruvate, 1 NADH is produced)
```
34
The products of the energy-payoff phase are produced through
substrate-level phosphorylation
35
How many steps are in the energy-investment stage?
1-5
36
How many steps are in the energy-payoff phase?
6-10
37
What happens to the pyruvate molecules in the mitochondrial matrix?
They are decarboxylated, releasing CO2
38
Where do pyruvate manipulations occur in prokaryotes? Why?
the cytosol, because they have no membrane-bound organelles
39
Once pyruvate looses CO2, it is a ___ molecule
2-carbon
40
What happens to the pyruvate after is looses CO2?
It undergoes an oxidation to become a 2-carbon acetyl group
| This oxidation reaction also reduces NAD+->NADH
41
Once made, what happens to the acetyl group?
It binds to Coenzyme A (CoA)
42
What are pyruvate manipulations carried out by?
pyruvate dehydrogenase
43
What do the pyruvate manipulations produce per glucose?
2 CO2
2 NADH
2 Acetyl-Coa
44
Other names for the Kreb's Cycle
the citric acid cycle
| the tricarboxylic acid (TCA) cycle
45
Where does the Kreb's cycle occur?
- the mitochondrial matrix in eukaryotes
| - the cytosol in prokaryotes
46
What is the first step of the Kreb's cycle?
a 2-carbon acetyl-CoA joins 4-carbon oxaloacetate to form 6-carbon citrate
47
What happens to citrate once made?
Undergoes rearrangements, where it looses 2-carbons as CO2
48
What happens each time CO2 is released from citrate?
NAD+ is reduced to NADH
49
What happens to the 4-carbon molecule after CO2 is released?
It progresses through the rest of the Kreb's cycle, producing GTP
50
How is GTP produced?
substrate-level phosphorylation
51
What is GTP?
guanosine triphosphate, an RNA nucleotide triphosphate (similar to ATP)
52
What happens to the 4-carbon molecule after GTP is made?
passes electrons to flavin adenine dinucleotide (FAD)
53
What is FAD?
an electron-carrying coenzyme similar to NAD+
54
What happens to FAD once made?
undergoes reduction to make FADH2
55
What happens to the 4-carbon molecule once FAD is made?
it transforms into oxaloacetate, reducing NAD+-> NADH in the process
56
The Kreb's cycle produces
- 2 CO2
- 3 NADH
- 1 FADH2
- 1GTP
57
How many times does the Kreb's cycle occur per glucose?
Twice- once for each Acetyl-Co-A/pyruvate
58
One glucose molecule results in what after going through the Kreb's cycle?
- 4 CO2
- 6 NADH
- 2 FADH2
- 2 GTP
59
Oxidative phosphorylation encompasses what components?
electron transport chain and chemiosmosis
60
What is the electron transport chain (ETC)?
made up of proteins and molecules that pass high-energy electrons from one component to the next
61
With each transfer, the electrons release ___ that the ETC uses to form an _____.
free energy
| electrochemical gradient
62
Chemiosmosis uses energy stores in the electrochemical gradient to _____
synthesis ATP
63
As electrons reach the end of the ETC, they are passed to an O2 molecule to form
water
64
What is the final electron acceptor for aerobic ETCs?
oxygen
65
Where is the ETC in eurkaryotes?
the mitochondrial inner membrane
66
Where is the ETC in prokaryotes?
along the cell membrane
67
ETC proteins are four large clusters called
protein complexes I-IV
68
Why do high-energy electrons pass through the ETC?
because each ETC protein is more electron hungry than the last
69
How does the ETC operate?
Through a series of oxidation-reduction (redox) reactions
| -with each transfer of electrons, the electron source becomes oxidized while the electron target becomes reduced
70
As redox reactions occur, the ___ pump protons from the mitochondrial matric into the intermembrane space, forming an ___
protein complexes
| electrochemical gradient
71
The ____ gradient will be harnessed to create ATP
chemiosmotic
72
What are the electron donors?
NADH and FADH2
73
Which of the reduced coenzymes are more effective and why
NADH, is travels directly to complex I
74
What happens to NADH/FADH2 once it contacts its respective complex?
it becomes oxidized to NAD+/FAD and can be used as a substrate in earlier stages of oxidative phosphorylation
75
As NAD+/FAD is regenerated, its complex undergoes a ____
reduction
76
oxidative phosphorylation directly depends on ___ as the _____
oxygen
| final electron acceptor of aerobic ETCs
77
oxidative pyruvate oxidation and Krebs cycles depend ___ on oxygen
indirectly
78
How does chemiosmosis synthesis ATP?
harnesses energy stored within the proton gradient as protons diffuse across the inner membrane from an area of high concentration(intermembrane space) to low concentration(mitochondrial matrix)
79
Where is NADH oxidized?
Complex I
80
Where is FADH2 oxidized?
Complex II
81
Electrons travel from ___ to ___ as the terminal electron acceptor, producing ____ in the ___
Complex IV
oxygen
water
matrix
82
Electrons released from FADH2 are used for pumping protons at
Complexes III and IV
83
The ___ is acidic due to the proton gradient
intermembrane space
84
Protons travel down their electrochemical gradient though ___
ATP synthase
85
ATP synthase relies on the ___ of chemiosmosis
proton motive force
86
What is the Gibbs free energy value of aerobic respiration?
-686kcal/mol glucose
87
aerobic respiration is a ___ reaction
exergonic
88
How many ATP are made from oxidative phosphorylation in eukaryotes?
36-38/glucose
89
A single NADH produces
3 ATP
90
A single FADH2 produces
2 ATP
91
Which produces more ATP? NADH from the cytosol or elsewhere? Why?
NADH produced elsewhere (not via glycolysis in the cytosol) generates more ATP because NADH needs a shuttle to get from the cytosol to the mitochondria
92
NADH from glycolysis in eukaryotes produce how many ATP?
4-6
93
NADH from glycolysis in prokaryotes produce how many ATP?
6 ATP
94
How many ATP do prokaryotes produce from aerobic respiration?
38 ATP
95
What happens when oxygen isn't available to be the final electron acceptor?
the processes that follow glycolysis does not occur and NAD+ is not regenerated
96
What is fermentation
an anaerobic pathway that oxidizes NADH-> NAD+ so that glycolysis can continue making ATP
97
What does lactic acid fermentation produce? How?
NAD+
| NADH transfers its electrons to pyruvate, regenerating NAD+ and reducing pyruvate into lactate/lactic acid
98
What is the Cori cycle?
a process humans undergo once oxygen becomes available again to convert lactate back into glucose
99
The Cori cycle transports ___ from the ___ through the bloodstream to ___ cells. Once there, the lactate can ___ back into ____. Pyruvate can form glucose through ____
```
lactate
myocytes
liver/hepatocytes
oxidize
pyruvate
gluconeogenesis
```
100
How many ATP are required to form pyruvate in the Cori Cycle?
6 ATP
101
What is the only organ that can release glucose into the blood and why
liver
| it is the only organ with the enzyme to reverse hexokinase
102
Alcohol fermentation regenerates __ for glycolysis to continue making 2 ATP
NAD+
103
In alcohol fermentation, pyruvate is ____ to lose carbon as ___
decarboxylated
| CO2
104
The leftover molecule from decarboxylation is ___
acetaldehyde
105
NADH reduces ____ into ___, ___ back to NAD+ in the process to continue undergoing fermentative glycolysis
acetaldehyde
ethanol
oxidizing
106
What are obligate aerobes
organisms that can only metabolize fuel via aerobic respiration and cannot undergo fermentation
107
What are obligate anaerobes
organisms that only metabolize fuel via anaerobic respiration/fermentation
-oxygen is toxic to them
108
What are facultative anaerobes
can utilize aerobic respiration, anaerobic respiration or fermentation. Undergo aerobic respiration is oxygen is present since it produces more ATP
109
What are microaerophiles?
cannot live without oxygen. Cannot undergo anaerobic respiration or fermentation. High concentrations of oxygen are harmful to them
110
What are aerotolerant organisms
cannot use oxygen, only use anaerobic respiration/fermentation
-presence of oxygen is not toxic
111
What is the storage form of glucose
glycogen
112
Where does glycogen enter cellular respiraiton
glycolysis
113
What is the process of breaking down glycogen
glycogenolysis
114
Glycogen if broken down to ___, and thus does not require hexokinase
Glucose-6-phosphate
115
Glycogen is a highly branched ___ (polymer of many monomeric carbohydrates_
polysaccharide
116
Carbohydrates are catabolized to provide
4 kcal/gram
117
glycogen is hard to store because it is
hydrophilic and attracts water
118
Where is glycogen stored
liver (2/3)
| muscle (1/3)
119
When fuel sources are abundant, ___ occurs
glycogenesis
120
Fats exist as
triacylglycerides/triglycerides
121
fatty acid tails of TAGs are attached to the glycerol backbone via__, formed by____
ester linkages
| dehydration reactions
122
___convert TAGs into FFAs and alcohols
lipases
123
digesting a TAG with a lipase is called
lipolysis
124
Humans absorb ingested fats through ___ of the __ as ____ and ___. Once in the cell, they reform into TAGs
enterocytes
SI
Monoglycerides and FFAs
125
TAGs, proteins, phospholipids and cholesterol pair up in enterocytes, forming
chylomicrons (lipoproteins)
126
Chylomicrons leave enterocytes and enter ___ that deliver fats to the rest of the body
lacteals
127
____ store TAGs, forming ___
adipocytes
| adipose tissue
128
Before a TAG can enter an adipocyte from a chylomicron, ___ must act on it to break it down to ___ and ___. Once inside the adipocyte, the TAG will reform
lipase
MAG
FFA
129
What is lipolysis
breakdown of fats
130
When enzyme performs lipolysis
hormone sensitive lipase
131
___ can also transport FFAs
albumin
132
Why are LDLs considered unhealthy
they deliver cholesterol to peripheral tissue, clogging blood vessels
133
Why are HDLs considered healthy
They take cholesterol away from peripheral tissue and deliver it to the liver to make bile
134
Once in the liver, glycerol can undergo ___ or___
glycolysis
| gluconeogenesis
135
FFAs enter cell respiration as
acetyl-CoA
136
What is beta-oxidation and where does it occur
converts FFA to acetyl-coA
| occurs in the mitochondrial matrix
137
Fats yeild how much energy
9kcal/gram
138
Before FA can enter beta oxidation, what must occur?
activate the FA chain with ATP
139
What happens to the FA once ATP is invested?
a series of cleavages into 2-carbon acetyl-CoA
140
What happens to Acetyl-Coa once made
it enters the Krebs cycle, producing NADH and FADH2
141
What is the least desirable fuel source?
proteins
142
Proteins broken down produce
Amino Acids
143
Proteins provide how much energy
4kcal/gram
144
What is the preferred energy source
carbohydrates
145
What must happen to amino acids before they undergo cell respiration?
oxidative deamination in the liver
146
What is oxidative deamination
Ammonia is removed from the amino acids to create a molecule easier to shuttle into cellular respiraiton
147
Ammonia is __ to vertebrates
toxic
148
Insects, reptiles and birds convert ammonia to ___ before excreting it
uric acid
149
Sharks, amphibians, and mammals convert ammonia to ____ before excreting it as ___
urea
| urine
150
How to aquatic species and invertebrates excrete ammonia?
directly as ammonia
151
Amino acid byproducts of oxidative deamination can enter cellular respiration at ____ depending on ___-
various points
| the starting amino acid
152
Why is proteolysis an inefficient fuel source
it requires energy to get amino acid byproducts into cellular respiration
153
Why are proteins a last resort in cellular respiration
cells need a pool of amino acids to make the proteins they use to carry out functions
154
Proteins can contribute to ___
gluconeogenesis
155
After the larynx, air flows into the
trachea
