Part 1: Biochemistry (AA’s, DNA/RNA, Macromolecules) Flashcards
(207 cards)
1
Q
All amino acids exist in the L form except for
A
Glycine
2
Q
Why is Glycine not in the L form?
A
It doesnt contain a chiral carbon
3
Q
Chiral carbons have different…
A
Compounds at each binding site
4
Q
All Amino Acids are _____________. (Can act as an acid or a base)
A
Amphoteric
5
Q
Name all of the Essential Amino Acids: (10)
A
[PVT TIM HALL]
Phenylalanine
Valine
Tryptophan
Threonine
Isoleucine
Methionine
Histidine
Arginine
Leucine
Lysine
6
Q
What amino acid is essential in a child but not an adult?
A
Histidine
7
Q
What are the purely ketogenic amino acids?
A
Leucine & lysine
8
Q
What amino acid is the precursor to carnitine?
A
Lysine
9
Q
What molecule takes fatty acids into the mitochondria for B Oxidation?
A
Carnitine
10
Q
What are the Aromatic Amino acids?
A
Phenylalanine, Tyrosine, Tryptophan
11
Q
What aromatic amino acid has an indole ring?
A
Tryptophan
12
Q
What amino acids contain sulfur?
A
Cysteine & Methionine
13
Q
What are the branched chain amino acids?
A
Isoleucine
Leucine
Valine
14
Q
What disease results from the inability to break down branched chained amino acids?
A
Maple syrup urine disease
15
Q
What are the acidic amino acids?
A
Aspartate & Glutamate
16
Q
What are the Basic (not acidic) amino acids?
A
Histidine
Lysine
Arginine
17
Q
When do basic amino acids have the greatest positive net charge?
A
At normal blood pH
18
Q
Protein source and its limiting amino acid: Wheat & rice
A
Lysine
19
Q
Protein source and its limiting amino acid: Legumes
A
Tryptophan
20
Q
Protein source and its limiting amino acid: Maize
A
Lysine & Tryptophan
21
Q
Protein source and its limiting amino acid: Pulses
A
Methionine or Cysteine
22
Q
Protein source and its limiting amino acid: Egg, Chicken
A
None
23
Q
Phenylalanine is converted into…
A
Tyrosine
24
Q
Deficiency of phenylalanine hydroxylase leads to ____________ meaning ______________.
A
Phenylketonuria (PKU); cant convert to tyrosine
25
Tyrosine is converted into…
L Dopa -> Dopamine -> Norepinephrine -> Epinephrine
OR
L Dopa -> Melanin
OR
T3, T4
26
What is the result of not being able to convert L Dopa to Melanin?
Albinism
27
Histidine is converted into…
Histamine
28
Tryptophan is converted into…
Serotonin -> melatonin
OR
Niacin -> Nicotinamide
29
For every ___ kg of body weight we need ___ g of protein.
10; 8
30
What does isoelectric point mean?
PH when an amino acid has no net electrical charge (neutral)
31
What does Zwitter Ion mean?
An amino acid at its isoelectric point
32
Glutathione = ___peptide of _________ + _________ + ____________.
Tri peptide; Glycine, Glutamate, Cysteine
33
What mineral is for the enzyme Glutathione Peroxidase?
Selenium
34
Example of polypeptide hormones:
Insulin & Glucagon
35
Examples of catecholamines:
Epinephrine, Norepinephrine & dopamine
36
Examples of steroids:
Testosterone, cortisol, estrogen, progesterone
37
A peptide bone is a type of _______ bond that is…
Amide; specific for all proteins
38
Primary protein structure characteristics:
Linear sequence of amino acids
39
Secondary protein structure characteristics:
Alpha helices & beta pleated sheets both held together by hydrogen bonds
40
Examples of a secondary protein structure (3)
1) fibrous protein’s collagen
2) silk
3) 2 DNA strands together
41
Tertiary protein structure characteristics:
Contains disulfide bond & folding of single polypeptide chain in solution
42
What is the classic example of a tertiary protein structure?
Myoglobin
43
Quaternary protein structure characteristics:
2 or more polypeptide chains to make a functional protein & contains Hydrogen and Disulfide bonds
44
What is the classic example of a quaternary protein structure?
Hemoglobin
45
Enzymes act on the…
Substrate
46
Enzymes _______ rate of a reaction by _____________________.
Increase; lowering the activation energy
47
All enzymes are considered…
Catalysts
48
Km is a measure of what?
The affinity that an enzyme has toward the substrate
49
Km and Affinity have an ___________ relationship, therefore…
Inverse; if you increase Km affinity decreases
50
What is Vmax?
The max velocity of an enzyme
51
What is the equation for Km?
Km = 1/2 Vmax
52
What are the 3 major factors that affect the reaction velocity of an enzyme?
1) Substrate concentration
2) Temperature
3) pH
53
Km is the amount of ___________ required to reach __________.
Substrate; 1/2 Vmax
54
What is the effect of competitive inhibitors on Km and Vmax?
Km: increases
Vmax: does not change
55
What is the effect of noncompetitive inhibitors on Km & Vmax?
Km: does not change
Vmax: decreases (will take longer to reach Vmax)
56
What does Gibb’s free energy measure?
The amount of energy available to see if a reaction is energetically feasible
57
If Gibbs free energy is positive, what does this mean? (Triangle G)
Reaction is non-spontaneous (endorgonic) & unfavorable
58
If Gibbs free energy is neutral, what does this mean? (Triangle G)
The reaction is at equilibrium
59
If Gibbs free energy is negative, what does this mean? (Triangle G)
Reaction is spontaneous (exergonic) & favorable
60
Vitamins are converted into __________ while minerals are converted into ____________.
Vitamins -> Coenzymes
Minerals -> Cofactors
61
The term reduction means
Gaining a hydrogen
62
What is the most active form of Iron?
Fe3+ (Ferric)
63
What is the most absorbable form of iron?
Fe2+ (Ferrous)
64
1) What form of Iron is found in food?
2) What form is absorbed by intestines?
3) What form is used by the body?
1) Fe3+
2) Fe2+
3) Fe3+
65
1) What converts Fe3+ to Fe2+?
2) What converts it back to Fe3+ to be used in the body?
1) Vitamin c
2) Cu2+
66
A deficiency of ____________ or ___________ results in tetany. Why?
Mg or Ca; because they track together
67
What vitamins and minerals are antioxidants?
Vitamins A,C,E
Selenium
Glutathione
Lipoic Acid
CoQ10
68
What hormone increases serum calcium?
PTH
69
What hormone decreases serum calcium?
Calcitonin
70
In monosaccharides, the aldehyde group is always on __________ and the ketone is always ___________.
C=O on Carbon #1; C=O on Carbon #2
71
If there are 5 carbons on a monosaccharide it is known as ____________. 6 carbons?
5: Pentose
6: hexose
72
What is a Carbonyl group?
C=O (double carbon bond to Oxygen)
73
What monosaccharides are aldohexoses?
- Glucose
- Galactose
- Mannose
74
What monosaccharides are aldopentoses?
Ribose
75
What monosaccharides are ketohexoses?
Fructose
76
What is the Monosaccharide formula?
Cn(H20)n
Where “n” is the number of carbons
Multiply the 2 by the number of carbons***
77
What is an isomer?
Different compounds with the same chemical formula
78
Examples of isomers
Glucose, Fructose & Galactose (C6H12O6)
79
What is an epimer?
Monosaccharide that differs around one specific carbon
80
What 2 substances are C-4 epimers?
Glucose & Galactose
81
What 2 substances are C2 epimers?
Glucose & Mannose
82
What is an Enantiomer? Example?
Mirror image of the same compound
L and D-Glucose
83
When are Anomers formed?
When sugars cyclize; and they are designated either alpha or beta
84
Fischer projection vs. Haworth projection of monosaccharides:
Fischer: linear stick figure
Haworth: Cyclized form
85
Sucrose is _____________ (__) + _____________ (__)
Glucose (alpha 1) + Fructose (beta 2)
86
Lactose is _____________ (__) + _____________ (__)
Galactose (beta 1) + Glucose (beta 4)
87
Maltose is _____________ (__) + _____________ (__)
Glucose (alpha 1) + Glucose (alpha 4)
88
Isomaltose is _____________ (__) + _____________ (__)
Glucose (alpha 1) + Glucose (alpha 6)
89
Cellobiose is _____________ (__) + _____________ (__)
Glucose (beta 1) + glucose (beta 4)
90
What can break (beta 1, beta 4) in lactose?
Lactase
91
Amylopectin breaks into…
Maltose & isomaltose
92
What can break (alpha 1, alpha 4) linkages to form maltose?
Amylase
93
Amylos ebreaks only into
Maltose
94
What is known as homopolymers of glucose?
Polysaccharides
95
Polysaccharides in humans:
Glycogen
96
Polysaccharides in plants:
1) Amylose
2) Amylopectin
3) Cellulose
97
What is the branch point of glycogen?
Alpha 1,6 linkage
98
What breaks amylose into maltose?
Alpha-amylase
99
What are Glycosaminoglycans (GAGs)?
Large complex of negatively charged heteropolysaccharides which bind large amounts of water
100
What is the major structural unit of Glycosaminoglycans (GAGs)?
Repeating disaccharides unit (protein sugar molecules)
101
What are the most common GAGs?
Hyaluronic Acid in synovial fluid & Chondroitin Sulfate in cartilage, tendons and ligaments
102
What type of bonds is a characteristic of fats?
Ester bonds
103
Triacylglycerols have __________________ esterified to a ___________ ____________.
3 fatty acids; glycerol backbone
104
A glycerol backbone consists of:
An acid + an alcohol
105
An ester bond consists of a n
Alcohol + acid
106
What are the most predominant form of fats/lipids in the body & diet?
Triacylglycerols
107
Where does glycerol come from?
Glucose
108
What are fatty acids composed of?
Nonpolar hydrocarbon tails & polar carboxylic acid head
109
What type of bond do unsaturated fatty acids have?
Double bonds
110
What do double bonds do to melting and freezing points of fatty acids?
Melting point: decreases it
Freezing point: raises
111
Naturally occurring double bonds exist in what configuration?
Cis configuration
112
What 3 things does Hydrogenation do?
1) raises melting point / decreases freezing point
2) increases shelf life
3) makes trans fats
113
Oxidation involves _____ of a Hydrogen
Loss
114
Reduction involves _____ of a hydrogen
Gain
115
To generate an unsaturated fat from a saturated fat _______ is required
Oxidation
116
What are the essential fatty acids?
Linoleic acid (omega 6)
Linolenic acid (omega 3)
Arachidonic acid (omega 6)
117
What is Linoleic acid (omega 6) found in?
Sunflower, safflower and corn oil
118
What is Linolenic acid (Omega 3) found in?
Flax oil
119
What is arachidonic acid (omega 6) found in?
Animal products (diary & red meat)
120
What is the precursor to prostaglandins?
Arachodonic acid
121
What is the most saturated oil?
Coconut oil
122
4 Saturted fats:
1) Laurie acid
2) myristic acid
3) palmitic
4) stearic
123
4 Unsaturated fats:
1) Oleic acid
2) Linoleic acid
3) Linolenic acid
4) arachidonic acid
124
How many Carbons do the following have?
1) Lauric Acid
2) Myristic Acid
3) Palmitic Acid
4) Stearic Acid
1) 12
2) 14
3) 16
4) 18
125
Oleic Acid has how many carbons and how many (C=C) bonds?
18 / (1 C=C)
126
Linoleic Acid has how many carbons and how many (C=C) bonds?
18 / (2 C=C)
127
Linolenic Acid has how many carbons and how many (C=C) bonds?
18 / (3 C=C)
128
Arachodonic Acid has how many carbons and how many (C=C) bonds?
20 / (4 C=C)
129
Phospholipids contain
2 fatty acids & a polar head group which is esterified to glycerol-3-phosphate
130
What is the major component of membrane lipids?
Phospholipids
131
What are the 2 classes of non glycerol lipids?
Sphingolipids & Steroids
132
What is the major lipid component of myelin sheath?
Sphingomyelin
133
A deficiency of sphingomyelinase results in
Niemann-Pick Disease
134
What is the most abundant Sterol in humans?
Cholesterol
135
Cholesterol is derived from…
acetyl CoA
136
Path of Acetyl CoA to steroid hormones (6 steps)
Acety CoA -> HMG-CoA -> Mevalonate -> Squalene -> Cholesterol -> Steroid hormones
137
What is the rate limiting enzyme of cholesterol synthesis?
HMG-CoA reductase
138
What does HMG-CoA reductase do?
Converts HMG-CoA -> mevalonate
139
What is the rate limiting enzyme in Steroid biosynthesis is…
Desmolase
140
What does the enzyme desmolase do?
Converts cholesterol -> pregnenolone -> progesterone
141
Where is cholesterol eliminated?
The feces
142
What 2 things bind to increase elimination of cholesterol?
Fiber & Bile Salts
143
What is the rate limiting enzyme of Ketone body synthesis?
HMG-CoA Synthase
144
Lipoproteins are composed of
A monolayer of polar lipids and proteins which surround a hydrophobic core of cholesterol esters and/or triglycerides
145
Where are chylomicrons produced and secreted from?
Intestinal mucosal cells in response to dietary intake of fats
146
What carries triacylglycerides to peripheral tissues?
Chylomicrons
VLDL (from liver to peripheral tissues)
147
Where are VLDL synthesized and secreted from?
Liver
148
LDL is derived from…
VLDL
VLDL -> IDL -> LDL
149
Function of LDL
Transport cholesterol from liver to peripheral tissues
150
What contains the most cholesterol?
VLDL
Chylomicrons
LDL
HDL
LDL
151
Where is HDL synthesized and secreted from?
Liver
152
Function of HDL:
Transport cholesterol from peripheral tissues back to the liver
153
High LDL levels ________ risk of Heart disease
Increase
154
High plasma levels ______ risk of heart disease
Decrease
155
What enzyme is required for the uptake of triglycerides carried by VLDL and Chylomicrons?
Lipoprotein Lipase
156
List the Lipoproteins from highest density to lowest:
HDL, LDL, IDL, VLDL, Chylomicrons
157
List the Lipoproteins from Biggest to Smallest in size:
Chylomicrons, VLDL, IDL, LDL, HDL
158
What are DNA and RNA composed of?
Phosphate, pentose sugar & nitrogenase base
159
What pentose sugar is in DNA? RNA?
DNA: deoxyribose
RNA: ribose
160
The formation of deoxyribose from ribose is what type of reaction?
Reduction because you gained a hydrogen
161
The purine nitrogenous bases are…
Adenine & Guanine
162
Purine Nitrogen is derived from what amino acids: (3)
Aspartate
Glycine
Glutamine
163
What is the rate limiting enzyme of purine breakdown?
Xanthine oxidase
164
What are the Pyrimidines of DNA and RNA?
DNA: Thyine
RNA: Uracil
BOTH: Cytosine
165
Nucleosides = _____________ + _____________
Pentose sugar + nitrogenous base
166
Nucleotides = _______________ + _____________ + _____________
Pentose sugar + nitrogenous base + phosphate
167
What are the purines and pyrimidines of DNA?
Purines: adenine & guanine
Pyrimidines: cytosine & thymine
168
What is DNA associated with?
Histones
169
Histones are the chief component of ___________
Chromatin (they act as spools around which DNA winds)
170
What is the base pairing pattern of DNA?
A-T & G-C
171
What is the base pairing of RNA?
There is none, it’s single stranded
172
What Pyrimidines replaces in RNA compared to DNA?
Uracil replaces Thymine
173
What type of bonds are in DNA and RNA?
Phosphodiester bonds
174
Phosphodiester bonds in DNA and RNA link between…
The 3 Carbon of one sugar and the 5 Carbon of another sugar
175
Phosphodiester bonds are _________ bonds.
Covalent
176
Hydrogen bonds are only in _______. (DNA or RNA)
DNA
177
DNA replication occurs in the _________ during the ________ of the cell cycle.
Nucleus; S Phase
178
What direction does DNA replication follow?
From 5 carbon to the 3 carbon
179
DNA replication is considered _______ and _________.
Anti-parallel & non-comparable
180
What is the enzyme responsible for DNA replication?
DNA polymerase
181
DNA transcription turns DNA into
MRNA
182
DNA Transcription occurs in the
Nucleus
183
DNA Transcription follows what direction?
From the 5 Carbon to the 3 Carbon
184
Every 3 bases in a strand of mRNA is called what?
Codon
185
What does a single Codon do?
Encodes for a single amino acid
186
What enzyme is responsible for DNA transcription?
RNA Polymerase
187
What is the 1st amino acid that is coded during DNA transcription?
Methionine
188
What are start codons?
AUG (MC)
GUG
189
What are the stop codons?
UAA, UGA & UAG
190
Translation occurs in the
Cytoplasm on the Rough ER
191
Steps of Translation: (4)
1) ribosomes expose 2 codons
2) codon recognized by anticodon on tRNA molecule
3) tRNA is bound to a specific amino acid
4) peptidyl transferase links 2 amino acids to begin synthesis of polypeptide chain
192
Steps of protein synthesis: (3)
1) Ribosomes read mRNA in 5 -> 3 carbon direction
2) synthesis proceeds from N to C terminus
3) always add amino acid @ C terminus during translation
193
Reverse transcription brings ______ back to ______
RNA; DNA
194
Examples of Catablic pathways: (3)
1) GLycolysis
2) lipolysis
3) glycogenolysis
195
What is a catabolic pathway?
Breakdown of macromolecules into simple precursors to generate ATP to reduce power (NADH, FADH)
196
What is an Anabolic pathway?
Synthesis of macromolecules from simple precursors (ATP generated from catabolic pathways are used to drive anabolic reaction)
197
Examples of anabolic pathways: (4)
1) gluconeogenesis
2) lipogenesis
3) glycogenesis
4) Nucleic acid synthesis
198
Definition of Phosphatase
Removes a phosphate
199
Definition of Phosphorylase
Adds a phosphate
200
Definition of Kinase
Moves a phosphate around
201
Dehydrogenase is used in
Oxidation and reduction reactions
202
Definition of Carboxylase
Add a carbon
203
Definition of decarboxylase
Removes a carbon
204
What amino acids are NOT glucogenic?
Leucine & Lysine
205
What amino acids are neutral?
Serine, Threonine, Asparagine, Glutamine
206
What amino acids donate Nitrogen for purines & Pyrimidines?
Glutamine, Aspartate & Asparagine
207
What is the # of Carbons in Arachodonic Acid?
20 (count in answer choices to eliminate)
