Exam 1 (9/2-9/5) Flashcards
(154 cards)
1
Q
One gram Carb= ? kcal
A
4
2
Q
One gram fat= ____kcal
A
9
3
Q
Do we usually store energy as fats or carbs? Why?
A
Fats (Lipids) because it doesnt interact with water like carbs do
4
Q
Two types of Phospoglycerides
A
Phosphoglycerides & Sphingolipids
5
Q
Sphingolipids lack?
A
glycerol
6
Q
What are phospoglycerides made of?
A
gylcerol, 2 fatty acids, polar head group
7
Q
amphiphilic means?
A
hydrophilic and hydrophobic regions
8
Q
Steroids function in:
A
membrane components and hormones
9
Q
How many rings are in a steroid function?
A
four
10
Q
Two examples of steroids:
A
Cholesterol: membranes
Testosterone: male hormone
11
Q
Proteins are the _______ workhorse of the cell
A
primary
12
Q
List the four general functions of a protein:
A
- Enzymes
- Transport
- Packaging
- Structure
13
Q
Proteins are made of:
A
amino acids
14
Q
Amino Acids are composed of:
A
amino group, carboxyl group and side chain (R)
15
Q
central carbon is known as
A
alpha carbon
16
Q
How many amino acids are there?
A
20
17
Q
Peptide bond
A
linkage between 2 amino acids between carboxyl group of one amino acid an amino group of another amino acids
18
Q
Amino acids form chains called:
A
polypeptides
19
Q
Amino Group (chemical formula)
A
NH2
20
Q
Carboxyl group (chemical formula)
A
COOH
21
Q
condensation reaction
A
lose H20 and make bond
22
Q
Nucleic Acids function as:
A
Genetic Information, Template for Protein
23
Q
Nucleotides are building blocks of:
A
nucleic acids
24
Q
Nucleotides are made up of:
A
Five carbon sugar, phosphate group, and nitrogenous base
25
Ribose is the sugar is
RNA
26
Deoxyribose is the sugar in
DNA
27
Deoxyribose lacks
OH group on the second carbon and is more stable
28
Pyrimidines are what bases?
Uracil, Cytosine, and Thymine
29
Purines are made of what bases?
Adenine and Guanine
30
DNA bases:
A, T, C, G
31
RNA bases:
A, U, C, G
32
Nucleoside
Base and Sugar
33
Nucleotides are linked by:
Phosphodiester bonds between phosphate group of one nucleotide and hydroxol group of another nucleotide
34
DNA is ______ stranded and RNA is _____ stranded
double, single
35
In DNA, what type of bonds are between the bases?
Hydrogen
36
T/F: DNA is parallel
false, it is antiparallel
37
Between Adenine and Thymine there can be ____ hydrogen bonds
2
38
Between Guanine and Cytosine there are _____ hydrogen bonds?
3
39
ATP is
Energy storage molecule
40
Why is ATP such a good energy storage molecule?
Due to the phosphate groups.
41
Why do reactions occur in small controlled steps to transfer energy to carrier molecule?
so we dont lose energy as heat
42
Hydrolysis reactions are used when
you break phosphate bonds
43
Catabolic Pathways
breaking bonds
44
Anabolic Pathways
make bonds
45
How does the cell store energy?
Chemical bonds, chemical concentration gradient, electrical concentration gradient and electrochemical gradients
46
Thermodynamics
study of the relationship between free energy, heat and disorder in a system
47
1st Law of Thermodynamics
energy cannot be created or destroyed, just converted from one form to another
48
2nd Law of Thermodynamics
Within an isolated system disorder is always increasing
49
Entropy (S)
amount of disorder in the system
50
T/F: Energy is not required to restore order in a system
False, energy IS required
51
Increasing Disorder has a _____ delta S and decreasing disorder has a ____ delta S
+;-
52
Free energy
amount of energy available to do work; G
53
T/F: All reactions have a change in free energy
True
54
When energy is consumed there is a _____ delta G.
Positive
55
Endergonic Rxn
energy consumed; +delta G
56
Exergonic Rxn
energy released; - delta G
57
Enthalpy
heat content of a reacting system
58
Exothermic Rxn
releases heat and has a negative delta G
59
Endothermic Rxn
Put in or consume heat; positive delta G
60
dG= dH-TdS
relationship between G, H, S
61
When are reactions favorable?
when they are spontaneous; delta G is negative
62
When delta G is positive a reaction is or is not spontaneous
is not
63
If enthalpy is decreasing and entropy is increasing the reaction will be:
favorable
64
Condensation Rxn are energetically_______
un-favorable
65
Hydrolysis Rxn are energetically ______
favorable
66
Overall, you always want delta G to be?
negative
67
Why might carbs be a better fuel than lipids?
Body can breakdown carbs faster
68
RNA is more/less reactive
more
69
RNA is produced
when conditions require them to be produced
70
Energy from ________ reactions is used for _______ reactions
catabolic; anabolic
71
Are our bodies an isolated system?
No
72
Which is more disordered?
| 10 nucleotides or 10 nucleotides assembled into DNA?
10 nucleotides
73
Combining 10 nucleotides into a polymer is spontaneous or nonspontaneous
nonspontaneous
74
Are reactions involving the assembly of polymers usually condensation rxn or hydrolysis rxn?
condensation
75
In some reactions, the standard free energy is positive, but the reaction is favorable in the cell. How could this occur?
Concentrations can vary.
76
What characteristics are true of a reaction at equilibrium?
Delta G=0
Rate of forward reaction=rate of backward reaction
ratio of reactants to products is constant
77
Triagylcerol is made of:
1 glycerol and 3 fatty acids
78
Triacygycerol is mainly used for:
energy storage
79
Is Triacylglycerol unsaturated or saturated?
Both
80
How can we determine delta G:
dG=dGnot + RTlog(products/reactants)
81
Delta G not is:
the change in free energy under specific conditions in the cell
82
Is equilibrium the same in the presence and absence of an enzyme?
Yes!
83
Metabolic Pathways are composed of:
molecules and enzymes that are involved in a series of chemical reactions required for the cell to grow, survive, and reproduce.
84
Enzymes _______ reactions.
Catalyze or accelerate
85
How does enzymes catalyze reactions?
by lowering the activation energy of a reaction. they dont change the overall delta G
86
What needs to be overcome to proceed?
activation energy
87
In catalysis, are both reactions accelerated to the same degree?
Yes.
88
Oxidation is the ______ of electrons. Reduction is the ______ of electrons.
Loss; Gain
89
NAD+/NADH
| which is oxidized?
NAD
90
FAD/FADH2
| which is reduced?
FADH2
91
Out of the following, which would be considered the most oxidized?
1. CH4
2. CO2
3. CH3OH
4. C2H4
CO2
92
What do activated carriers do?
store energy until it is ready to be used
93
What is the most abundant activated carrier?
ATP, because of phophoanhydride bonds
94
Breakage of phosphanhydride bonds eliminates what?
Repulsion between negative charges
95
Acetyl CoA
high energy bond is present that can be broken to provide energy for another reaction
96
Thioester bond is between
CH3CO--S
97
Amino acids, fatty acids, and sugars are processed through a number of steps to yeild the energy storage molecule:
ATP
98
Where does glycolsis occur?
Cytosol
99
How many steps is glycolsis?
10 steps catalyzed by 10 different enzymes.
100
Does Glycosis occur under anaerobic (No O2) conditions?
yes.
101
Glycolysis yields:
2 pyruvate per 1 glucose
102
What is the net energy carrier production of glycolysis?
2 ATP & 2 NADH
103
What are the two phases of glycosis?
Preparatory and Pay-off Phase
104
What does the preparatory phase do?
preparing glucose for cleavage
105
In the preparatory phase how many ATP is consumed?
2
106
What reactions are part of the preparatory phase?
Rxn 1-4 (sometimes 5)
107
What is Step 1 of Glycolysis?
Name: Hexokinase
What happens: phosphorlyation of glucose, addition of phosphate traps glucose in cell
Reversible or Irreversible: Rxn is irreversable.
delta G= is negative
108
What is Step 2 of Glycolysis?
Name: Phosphohexose Isomerase
What happens: rearrangment of glucose to fructose
Reversible or Irreversible: Rxn is irreversable.
delta G= is negative
109
What is Step 3 of Glycolysis?
Name: Phosphofructokinase
What happens: addition of phosphate ensures both molecules are contained in the cell after cleavage of glucose
Reversible or Irreversible: Rxn is irreversable.
delta G= is negative
*First step where molecule is commited to going through glycolysis
110
What is Step 4 of Glycolysis?
Name: Aldolase
What happens: Glucose (6C) is cleaved into two 3C molecules
Reversible or Irreversible: Rxn is reversible due to cellular conditions
*only glyceraldhyde-3-phosphate can proceed
111
What is Step 5 of Glycolysis?
Name: Triose Phosphate Isomerase
What happens: phosphorlyation of glucose, addition of phosphate traps glucose in cell.
Reversible or Irreversible: Rxn is reversable.
112
How many irreversible reactions are in glycolysis?
3
113
Glycolsis Payoff phase is steps ___ thru ____?
6-10
114
What happens overall in the payoff phase?
Produces 4 ATP & 2 NADH
115
What is Step 6 of Glycolysis?
Name: Glyceraldehyde 3-phosphate dehydrogenase
What Happens: Redox rxn, forms high energy bond in product
Reversible or Irreversible: reversible
Produces: 1,3-Biphospoglycerate
116
What is Step 7 of Glycolysis?
Name: Phosphoglycerate kinase
What Happens: high energy bond from 1,3-biphospoglycerate provides energy for formation of ATP.
Reversible or Irreversible: reversible under cellular conditions
*First step where we generate ATP
117
What is Step 8 of Glycolysis?
Name: Phophoglcerate mutase
What Happens: movement of phosphate group (from 3 to 2)
Reversible or Irreversible: reversible
118
What is Step 9 of Glycolysis?
Name: Enolase
What Happens: removal of water creates high energy enol-phosphate linkage
Reversible or Irreversible: reversible
119
What is Step 10 of Glycolysis?
Name: Pyruvate Kinase
What Happens: synthesis of ATP, pyruvate formation
Reversible or Irreversible: irreversible
120
Are Steps 6 & 7 are coupled? If so, how?
Yes. In step 6, we are oxidizing carbon which releases energy. That energy is used to reduce NADH and form a high energy bond.
121
Fermenatations lead to
excretion of lactate
| excretion of alchohol and CO2
122
Fermenation occurs in what type of conditions?
anerobic
123
In what conditions does the citric acid cycle occur in?
aerobic
124
What do you put into glycolysis?
glucose, 2 ADP, 2Pi, and 2 NAD+
125
What do you get out of glycolysis?
2 Pyruvate, 2 NADH, 2H+, 2 ATP, 2 H2O
126
Citric acid cycle is also called
krebs cycle
127
where does the citric acid cycle occur in eukaryotes?
mitochondria
128
In the citric acid cycle, what must first happen to the pyruvate from glycolysis?
It has to be made into acetyl-CoA
129
Pyruvate Dehydrogenase happens in
mitochondrial nucleus
130
Pyruvate Dehydrogenase Complex
Complex of 3 enzymes that catalyze 5 reactions, located in mitochondrial matrix
131
Complex 1 in Pyruvate Dehydrogenase:
remove one carbon from pyruvate
132
Complex 2 in Pyruvate Dehydrogenase:
transfer of two carbons to CoA
133
Complex 3 in Pyruvate Dehydrogenase:
making sure reaction can continue to occur
134
Overall Energy Carrier Production from 1 acetyl-CoA (x2 for each glucose)
3 NADH, 1 FADH2, 1 GTP
135
What is Step 1 in the Citric Acid Cycle?
Name: Citrate Synthase
| What Happens: Hydrolysis of high energy thioester bond in Acetyl-CoA, making reaction favorable
136
What is Step 2 in the Citric Acid Cycle?
Name: Aconitase
| What Happens: Isomerization of citrate
137
What is Step 3 in the Citric Acid Cycle?
Name: Isocitrate dehydrogenase
What Happens: first of four oxidation steps
Yields: CO2 and NADH
138
What is Step 4 in the Citric Acid Cycle?
Name: alpha-ketoglutarate dehydrogenase complex
What Happens: second of four oxidation steps
Yields: NADH, CO2, and compound with high energy thioester bond
139
What is Step 5 in the Citric Acid Cycle?
Name: Succinyl-CoA synthetase
| What Happens: phosphate displaces CoA to make high energy intermediate. Phosphate is passed to GDP to make GTP
140
What is Step 6 in the Citric Acid Cycle?
Name: Succinate dehydrogenase
What Happens: third of four oxidation steps
Yields: FADH2
141
What is Step 7 in the Citric Acid Cycle?
Name: Fumarase
| What Happens: hydration reaction (add H2O)
142
What is Step 8 in the Citric Acid Cycle?
Name: Malate dehydrogenase
What Happens: fourth oxidation rxn; oxalacetate regeneration
Yield: oxaloacetate
143
Citric Acid Cycle
Series of Eight Rxn; regenerates oxaloacetate, releases 2 CO2, requires O2 for regeneration of NAD+ and FAD
144
Where does lactate excretion occur?
Skeletal muscle
145
Distinguish between the preparatory and payoff phase of glycolysis.
Preparatory phase consumes 2 ATP
| Payoff produces 4 ATP & 2 NADH
146
What are the net products of glycolysis?
2 Pyruvate, 2 ATP, 2 NADH, 2H+, 2 H20
147
Where does glycolysis occur?
Cytosol
148
Which reactions are irreversible in glycolysis?
Three phosphorylation steps catalyzed by kinases.
| Step 1, Step 3, Step 10
149
What is the first committed step?
Step 3
150
How do products from glycolysis enter the citric acid cycle?
Pyruvate must be processed to acetyl-CoA by the pyruvate dehydrogenase complex in the mitochondrial matrix in order for products to enter the citric acid cycle
151
Where does the citric acid cycle occur?
Mitochondrial Matrix
152
Which steps are redox in the Krebs cycle?
3, 4, 6, & 8
153
What are the net products of the citric acid cycle?
For each acetyl-CoA that enters the cycle, 3 NADH, 3H+, 1 FADH2, 1 GTP, 2 CO2.
154
What is regenerated in the final step of the citric acid cycle that keeps the cycle going?
Oxaloacetate
