Chapter 4 PPT Flashcards
1
Q
What is metabolism?
A
The sum of all chemical reactions in the body
2
Q
What is cellular metabolism?
A
sum of all chemical reactions occurring in a cell. Metabolic reactions usually occur in pathways or cycles
3
Q
What are the two metabolic reactions?
A
Anabolism and Catabolism
4
Q
What is Anabolism?
A
Small molecules are built into larger ones, requires energy
5
Q
What is Catabolism?
A
Larger molecules are broken down into smaller, releases energy
6
Q
Anabolism provides
A
materials for maintenance, cellular growth, and repair. Requires ATP made during catabolism
7
Q
Example of Anabolsim?
A
Dehydration Synthesis
8
Q
In Dehydration Synthesis, smaller
A
molecules are bound together to form larger ones
9
Q
What is produced in hydration synthesis?
A
H2O
10
Q
Anabolism used to produce
A
polysaccharides, proteins, and triglycerides
11
Q
Catabolism breaks
A
down larger molecules into smaller ones; ATP is produced
12
Q
Example of Catabolsim?
A
Hydrolysis
13
Q
Catabolism used to
A
decompose carbohydrates, proteins, lipids
14
Q
Catabolism uses
A
H2O to split the substances
15
Q
Catabolism is reverse of
A
dehydration synthesis
16
Q
All cells perform
A
catabolic and anabolic reactiosn
17
Q
Enzymes control
A
rates of both catabolic and anabolic reactions
18
Q
enzymes are globular proteins that
A
catalyze specific reactions
19
Q
enzymes increases
A
rates of chemical reactions
20
Q
enzymes lower
A
the activation energy necessary to start reactions
21
Q
Shape of enzyme is
A
vital to its functioning
22
Q
Factors that can alter conformation of an enzyme
A
Excess Heat Radiation Electricity Specific Chemicals Extreme pH Values Some Poisons
23
Q
What is Denaturation?
A
Inactivation of enzyme due to an irreversible chang in its conformation
24
Q
What is a “Metabolome”
A
All small molecules that are part of the metabolism in a cell, tissue, organ, organism
25
Human Metabolome Database stores
vast amounts of information about these molecules, also called :metabolites"
26
What are metabolic pathways?
Sries of enzyme-controlled reactions leading to formation of a product. Each new substrate is the production of the previous reaction
27
Names of enzymes often
Contain name of substrate, and ends in ase
28
Each step of a pathway is
catalyzed by a different enzyme
29
A regulatory enzyme that catalyzes one step of pathway typically
sets rate for entire reaction sequence
30
What is the rate-limiting enzyme ?
Number of molecules of this enzyme is limited. and is often the first enzyme in the reaction sequencec
31
What is a cofactor?
Non-protein substance that combines with the enzyme to activate it
32
Cofactor- some help fold
active site into proper conformation
33
Cofactor - some help bind
enzyme to substrate
34
Cofactor- can be
ion, element, or small organic molecule
35
Coenzyme is
organic molecule that acts as a cofactor.
36
Coenzyme - most are
vitamins, which are essential organic molecules that humans must get from their diet
37
Inborn Errors of Metabolism
Deficient or absent enzyme blocks metabolic pathway that it catalyzes. Results in accumulation of enzymes substrate, and a deficiency of its product
38
Example of Inborn Errors of Metabolism
Phenylketonuria (PKU)
39
What is PKU?
Missing/nonfunctional enzyme blocks conversion of amino acid, phenylamine, into the amino acid, tyrosine. Excess phenylalnine enters blood and poisions the brain. Can be treated with special diet
40
Energy is
the capacity to change something, or the ability to do work
41
Common forms of energy
heat, light, sound, electrical energy, mechanical energy, chemical energy
42
Cellular respiration is a
process that transfers energy from molecules, and makes it available for cellular use
43
ATP carries
energy in a form the cell can use. Main energy carrying molecule in the cell.
44
ATP consists of what 3 portions?
Adenine
Ribose (A Sugar)
3 Phosphates In A Chain
45
SEcond and third phosphates are
attached by high energy bonds; energy can be quickly transferred to other molecules
46
Wen ATP loses terminal phosphate, it
becomes ADP
47
ADP can be converted back into ATP by
attaching a third phosphate, called phosphorylation
48
Phosphorlation requires
energy from cellular respiration
49
ATP and ADP cycle
back and forth between cellular respiration and energy-utilizing reactions
50
Energy is held in
chemical bonds, and released when bonds are broken
51
Oxidation releases energy from
glucose
52
In cells, enzymes initiate oxidation by
lowering activation energy
53
Energy is transferred to ATP, whats the ratio?
40% is released as chemical energy
| 60% is released as heat
54
Cellular Respiration of glucose occurs in what 3 interconnected reaction sequences?
Glycolysis (anaerobic)
Citric Acid Cycle (Aerobic)
ETC/Oxidative Phosphorylation (Aerobic)
55
Glycolysis and ETC are
stepwise reaction sequences
56
Citric Acid Cycle occurs in a
cycle; final products reacts to replenish original substrate
57
Cellular respiration of glucose requires
a supply of glucose and O2
58
Products of cellular respiration?
CO2
Water
ATP
Heat
59
Cellular Respiration includes what two reactions?
Aerobic; Require O2, make most of ATP
| Anerobic: DO not require O2, and make little ATP
60
Glycolysis is the first
reaction sequence of glucose breakdown
61
Glysolysis is a series of
10 reactiosn
62
Glycolysis breaks down
glucose (6-carbon) into 2 pyruvic acid (3-carbon) molecules
63
Glycolysis occurs in
cytosol
64
Glycolysis is in the
anaerobic phase of cellular respiration
65
Glycolysis yields
2 ATP molecules per glucose molecule broken down
66
3 Phases of Glycolysis
Phosphorylation of GLucose
Splitting/Cleavage of Glucose into 2 3-Carbon Molecules
Production of NADH, ATP, and 2 Molecules of Pyruvic Acid
67
Glycolysis; Phase 1
Phosphorylation
Glucose is phosphorylated; 2 APT is used
68
Glycolysis; Phase 2
Splitting
6-C molecule cleaves into 2 3-carbon molecules
69
Glycolysis; Phase 3
ATP Formation and Release of Electrons
2 Pyruvic Acid formed
4 ATP Formed
2 NADH and H+ Formed
70
In presence of O2,
NADH and H+ deliver electrons to the ETC, with oxygen as the final electron acceptor
71
In absence of O2,
there is no electron acceptor
72
How is Lactic Acid Formed?
When NADH and H+ deliver electrons and H+ back to Pyruvic Acid
73
Buildup of lactic acid inhibits
glycolysis, with atp production decreasing
74
Glycolysis produces much less
ATP than aerobic respiration
75
In anaerobic reactions, net gain of atp per molecule of glucose?
2
76
Aerobic Reactions Include
Synthesis of Acetyl Coenzyme A
Citric Acid Cycle
ETC
77
Aerobic reaction begins with
pyruvic aciid moving from cytosol to mitochondria
78
Pyruvic acid is used to produce
Acetyl CoA
79
End products of Aerobic Reaction is
CO2, H2O and up to 36 ATP per molecule of glucose
80
Citric Acid Cycle begins when
Acetyl CoA combines with oxaloacetic acid to produce citric acid
81
Citric acid is changed into
oxaloacetic acid thorugh a series of reactions
82
Citric Acid Cycle repeats as long as
pruvic acid and o2 are available
83
For each citric acid molecule
1 atp is produced
8 hydrogen atoms are transferred to NAD+ and FAD 2 CO2 are produced
84
ETC - NADH and FADH2 carry
hydrogen and high energy electrons to the ETC
85
ETC is a series of
enzyme complexes (electron cariers) located in the inner membrane of mitochondria
86
ETC- Energy from
electrons is transferred to the enzyme aTP synthase
87
ETC - ATP synthase
uses energy to catalyze phosphorylation to ADP to ATP
88
ETC - What is formed?
H2O is formed, with oxygen is the final electron "carrier"
89
Carbohydrate molecules from foods can enter catabolic pathways
for energy production
90
carbohydrate molecules from foods can enter anabolic pathways
for storage
91
carbohydrate molecules from foods can react
to form some of the amino acids
92
excess glucose can be converted into and stored as
glycogen and fat
93
Glucose - Glycogen
most cells, but liver and muscle cells store the most
94
Glucose - Fat
To store in adipose tissue
95
What is genetic information?
Instructions to tell cells how to construct proteins; stored in DNA sequence
96
What is a gene?
Sequence of DNA that contains information for making 1 protein
97
What is a genome?
Complete set of genetic information in cell
98
What is exome?
Small portion of genome that codes for proteins
99
What is agene expression?
Control of which proteins are produced in each cell type, in what amount, and under which circumstances
100
Nucleotides are
building blocks of DNA
101
Nucleotides consist of
5-carbon sugar, deoxyribose
A phosphate group
A nitrogenous base (A,C, G,T)
102
Backbone of each strand is a
sugar-phosphate chain
103
Bases from the 2 complementary strands link together by
hydrogen bonds: C-G, A-T
104
How are chromosomes formed?
When DNA wraps around histone proteins
105
Human genome contains
3.2 billion bits of information
106
What is DNA Replication?
Process that produces an exact copy of a DNA molecules; occurs during interphase
107
Step 1 in DNA Replication
Hydrogen bond breaks between base pairs
108
Step 2 in DNA Replication
Strands unwind and separate
109
Step 3 in DNA Replication
New nucleotides pair with exposed bases, under direction of DNA polymerase
110
Step 4 in DNA Replication
Other enzymes connect new sugar-phosphate backbone
111
genetic information store
correct sequence of amino acids for a polypeptide chain
112
Triplet Code
a sequence of 3 nucleotides that represent an amino acid, or signals beginning or end of a protein
113
What determines the amino acid sequence in a polypeptide?
Sequences of bases in a gene
114
Protein synthesis occurs in
cytoplasm
115
RNA copies and
transfers information from DNA to the cytoplasm
116
RNA molecules are single
strands of nucleotides
117
Complementary base pairing in RNA
A-U, C-G
118
Transcription
Process of copying DNA sequence onto an RNA sequence
119
mRNA
CArries genetic code from DNA to ribosome
120
RNA Polymerase
Enzyme that catalyzes the formation of mRNA from the proper strand of DNA
121
First Step in Transcription of mRNA
RNA polymerase recognizes correct strand of DNA to copy
122
Second Step in Transcription of mRNA
A section of DNA unwinds to expose the gene coding for the particular protein
123
Thrid Step in Transcription of mRNA
Complementary mRNA nucleotides pair with the DNA bases (Uracil used instead of Thymine)
124
Fourth Step in Transcription of mRNA
Termination signal indicates end of gene
125
Fifth Step in Transcription of mRNA
New mRNA strand is released, and DNA rewinds into double helix
126
Sixth Step in Transcription of mRNA
The mRNA now leaves the nucleus through a nuclear pore, and attaches to a ribosome in the cytoplasm
127
What is a codon?
Each amino acid is specified by a sequence of 3 bases in DNA
128
Protein synthesis occurs in
cytoplasm
129
mRNA leaves
nucleus and binds to ribosome, to act as template for protein synthesis
130
At the ribosome, the genetic code, carried by mRNA, is
used to synthesize a protein
131
What is Translation?
Process of converting the genetic code, carried by mRNA, into a sequence of amino acids that becomes a protein
132
Protein synthesis requires that
amino acids are added to growing polypeptide chain in proper sequence
133
tRNA aligns
amino acids during protein synthesis, along the mRNA strand on the ribosome
134
tRNA binds to
its amino acids, transports it to a ribosome, binds to the mRNA according to its sequence, and adds its amino acid to the growing polypeptide chain
135
Each tRNA contains
a sequence of 3 nucleotide bases, the anticodon, which binds to complementary codon on the mRNA strand
136
AS the ribosome moves down the mRNA, each
tRNA brings in its amino cid to be added to the growing protein
137
How many types of amino acids are there?
20
138
How many possible codons are there ?
64
139
What is the initiation codon?
AUG, codes for Methionine, and signals the start of a protein
140
How many codons are stop codons?
3
141
Protein synthesis occurs on
ribosomes
142
mRNA is used as
a template for protein syntehsis
143
tRNA brings
amino acids to the ribosome, and binds to mRNA, to ad its amino acid to the growing protein chain
144
Ribosomes are organelles composed of
rRNA and protein molecules
2 unequal subunits
145
Binding of tRNA and mRNA occurs in
association with a ribosome
146
Ribosomes move down mRNA molecule, bringing
in tRNAs carrying the proper amino acid to add to the growing protein chain
147
Amino Acids are joined by
peptide bonds
148
First step in Translation
A ribosome binds to the mRNA near the codon at the beginning of the messenger strand
149
Second step in Translation
A tRNA molecule that has the complementary anticodon brings its amino acid to the ribosome
150
Third step in Translation
A second tRNA brings the next amino acid to the ribosome
151
Fourth step in Translation
a peptide bond forms between the two amino acids, and the first tRNA is released
152
Fifth step in Translation
This process repeats for each codon in the mRNA sequence as the ribosome moves along its length, forming a chain of amino acids
153
sixth step in Translation
the growing amino acid chain folds into the unique conformation of a functional protein
154
seventh step in Translation
the completed protein molecule is released . The mRNA, ribosome, and tRNAs are recycles
155
Mutations are
changes in DNA sequence
156
Mutations occur when
bases are changed, added, or deleted
157
Mutations can be
spontaneous or induced
158
Spontaneous Mutation
Due to insertion of unstable base into DNA sequence
159
Induced Mutation
due to exposure to mutagents, chemicals, or radiation that causes mutation
160
Duchenne Muscular Dystrophy results from
a muttion in the gene coding for dystrophin; muscle cells collapse, resulting in severe muscle weakness
161
DNA repair
Correction of mismatched nucleotides by a repair enzyme
