Chapter 2 Export Flashcards
(156 cards)
1
Q
Term/Front
A
Definition/Back
2
Q
What is a polymer?
A
Large molecule made of repeated monomer subunits
3
Q
What are the building blocks of proteins?
A
Amino acids
4
Q
How many amino acids are there?
A
20
5
Q
What are polypeptides?
A
Long chains of amino acids
6
Q
What is the primary structure of proteins?
A
Chain of amino acids
7
Q
What is the secondary structure of proteins?
A
Alpha helix and beta sheet
8
Q
What is the tertiary structure of proteins?
A
3D Structure
Tertiary structure is formed when the secondary structures further fold by forming interactions and bonds between amino acids and R-groups of its different sections. Disulphide bonds can also from between cysteine amino acids to further stabiles the 3D structure
9
Q
What is the quaternary structure of proteins?
A
Multiple chains
10
Q
What are proteins also known as?
A
Polypeptides
11
Q
What is a proteome?
A
All proteins expressed by a cell or organism at a given time
12
Q
What is the function of enzymes?
A
Speed up chemical reactions
13
Q
What is catalase?
A
Enzyme that breaks down hydrogen peroxide
14
Q
What does amylase do?
A
Breaks down starch into maltose
15
Q
What is the function of transport proteins?
A
Control entry and exit of substances
16
Q
What are examples of structural proteins?
A
Keratin, elastin, collagen
17
Q
What is the role of hormones in proteins?
A
Chemical messengers that induce changes in cells
18
Q
What does insulin regulate?
A
Blood sugar levels
19
Q
What is the function of receptors?
A
Receive signals from the environment
20
Q
What is the role of antibodies?
A
Recognise and destroy pathogens
21
Q
What do motor proteins do?
A
Involved in muscle contraction and movement
22
Q
What is ferritin?
A
Storage of iron
23
Q
What is the chemical structure of an amino acid?
A
Central carbon, carboxyl group, amino group, R-Group, hydrogen atom
24
Q
What affects interactions between proteins?
A
Chemical properties of R groups
25
What are monomers?
Building blocks that join to form polymers
26
What are polymers of amino acids called?
Polypeptides or proteins
27
What is a monomer?
Smallest building block of a polymer
28
What is a condensation reaction?
Reaction where two monomers join to form a larger molecule, producing water
29
What is a peptide bond?
Chemical bond linking two amino acids
30
What is the primary structure of a protein?
Sequence of amino acids in a polypeptide chain
31
What is the secondary structure of a protein?
Arrangement into alpha-helices, beta-pleated sheets, or random coils
32
What is the tertiary structure of a protein?
Functional 3D shape of the protein
33
What is the quaternary structure of a protein?
Bonding of multiple polypeptide chains together
34
What is a prosthetic group?
Non-protein group bound to a protein, e.g., a vitamin or ion
35
What are nucleic acids?
Polymers of nucleotide monomers that store genetic information
36
What are the components of a nucleotide?
Phosphate group, pentose sugar, nitrogen-containing base
37
What is DNA?
Deoxyribonucleic acid, consists of two strands of nucleotides
38
What is the structure of DNA?
Two polynucleotide chains running antiparallel, joined by complementary base pairs
39
What does antiparallel mean in DNA?
Strands run in opposite directions, one 3'-->5' and the other 5'-->3'
40
What is RNA?
Ribonucleic acid, a single strand of nucleotides
41
What is the function of mRNA?
Carries genetic information from nucleus to ribosomes for protein synthesis
42
What is the function of tRNA?
Delivers specific amino acids to the ribosome
43
What is the function of rRNA?
Main structural component of ribosomes
| rRNA is a ribozyme which carries out protein synthesis in ribosomes
44
What sugar does RNA contain?
Ribose sugar
45
What base is used in RNA instead of Thymine?
Uracil
46
What sugar does RNA contain?
Ribose sugar
47
What base is used in RNA instead of Thymine?
Uracil
48
Is RNA single or double stranded?
Single stranded
49
What are the two types of nucleic acids?
DNA and RNA
50
What components make up nucleic acids?
Phosphate group, five-carbon sugar, nitrogenous base
51
What is the process of producing mRNA from DNA called?
Transcription
52
What is the process of translating mRNA into a protein called?
Translation
53
What is a triplet in DNA?
Sequence of three nucleotides coding for one amino acid
54
What is a codon in mRNA?
Sequence of three nucleotides coding for one amino acid
55
What does the start codon AUG code for?
Methionine
56
What are the stop codons?
UAA, UAG, UGA
57
What is the function of a promoter region?
Binding site for RNA polymerase to initiate transcription
58
What is the TATA box?
Common promoter sequence in eukaryotes
59
What are introns?
Non-coding DNA regions removed during RNA processing
60
What are exons?
Coding DNA regions transcribed and translated into protein
61
What does the termination sequence signal?
End of transcription
62
What is the role of the operator region?
Binding site for repressor proteins to inhibit gene expression
63
What is the leader region?
Section of DNA just upstream of the coding region
64
What is gene expression?
Production of functional gene products such as proteins
65
What is gene expression?
The production of functional gene products such as proteins or non-coding strands of RNA.
66
What are the stages of gene expression?
Transcription, RNA processing, Translation.
67
What happens during transcription?
Creation of pre-mRNA by converting DNA into RNA.
68
Where does transcription occur in eukaryotes?
Entirely within the nucleus.
69
Where does transcription occur in prokaryotes?
Directly in the cytoplasm.
70
What is the first stage of transcription?
Initiation.
71
What happens during initiation?
Transcription factors and RNA polymerase bind to the promoter region.
72
What happens during elongation?
RNA polymerase adds complementary RNA nucleotides to form pre-mRNA.
73
What happens during termination?
Transcription ends at the termination sequence, releasing pre-mRNA.
74
What is RNA processing?
Modification of pre-mRNA into mRNA for translation.
75
What is added to the 5' end of pre-mRNA?
5' methyl-G cap.
76
What is added to the 3' end of pre-mRNA?
3' poly-A tail.
77
What are introns?
Non-coding regions of DNA that are spliced out during RNA processing.
78
What are exons?
Regions of DNA that code for proteins and are retained during RNA processing.
79
What is splicing?
Process where introns are cut out and exons are joined together.
80
What is a spliceosome?
The enzyme that removes introns and joins exons during RNA processing.
81
What is alternative splicing?
Process where different exons may be removed, producing different mRNA molecules.
82
What is the significance of alternative splicing?
Allows a single gene to produce many different proteins.
83
What is the direction of pre-mRNA synthesis?
5' to 3' direction.
84
What is alternative splicing?
The process where different exons may be spliced, resulting in a single gene producing multiple different mRNA strands.
85
What is the role of translation?
Reading and converting the information in the mRNA molecule into a polypeptide chain.
86
What happens after pre-mRNA undergoes modifications?
It exits the nucleus and travels to a ribosome.
87
What are the three stages of translation?
Initiation, elongation, termination.
88
What occurs during initiation of translation?
The 5’ end of mRNA binds to ribosome; start codon (AUG) recognized; tRNA with anticodon (UAC) delivers methionine.
89
What occurs during elongation of translation?
mRNA is fed through ribosome; codons matched to tRNA anticodons; tRNA delivers amino acids, forming peptide bonds.
90
What marks the termination of translation?
Translation continues until stop codon on mRNA is reached, signaling the end of translation.
91
What happens to the polypeptide chain after translation?
It is released into the cytosol or endoplasmic reticulum.
92
What is transcription?
The process whereby a sequence of DNA is used as a template to produce a complementary sequence of mRNA.
93
What is precursor messenger RNA (pre-mRNA)?
The immediate product of transcription of a DNA sequence, requiring modifications before translation.
94
What is the function of messenger RNA (mRNA)?
Carries genetic information from the nucleus to the ribosomes.
95
What is transfer RNA (tRNA)?
RNA that recognizes specific codons on the mRNA strand and adds the corresponding amino acid to the polypeptide chain.
96
What is ribosomal RNA (rRNA)?
RNA that is a key structural component of ribosomes, which assemble proteins.
97
What is an enzyme?
An organic molecule, typically a protein, that catalyzes specific reactions.
98
What do regulatory genes code for?
Proteins that influence the expression of structural genes.
99
What are structural genes responsible for?
Producing proteins involved in the structure or function of a cell.
100
What is the role of regulatory proteins?
They can inhibit or increase the expression of structural genes.
101
What is an operon?
A group of multiple structural genes arranged to be efficiently controlled by a single promoter and operator.
102
What are structural genes arranged into for efficient expression control?
Operon
103
Where are operators located in relation to the promoter region?
Downstream
104
What do repressor proteins inhibit when bound to the operator region?
Transcription
105
What happens when the operator region is not bound by a repressor?
Transcription occurs
106
Do all somatic cells express the same genes?
No
107
What does the trp operon produce?
Tryptophan
108
What are the structural genes in the trp operon?
trpE, trpD, trpC, trpB, trpA
109
What controls the trp operon?
A regulatory gene upstream
110
What happens at high levels of tryptophan?
Transcription is stopped
111
What happens at low levels of tryptophan?
Transcription is started
112
What is repression in the context of the trp operon?
Inhibition of transcription by repressor protein
113
What causes the repressor protein to activate?
Binding of tryptophan
114
What is attenuation in the regulation of the trp operon?
Early stopping of transcription
115
Where is the attenuator sequence located?
At the end of the leader region
116
What does the attenuator sequence contain?
Two consecutive trp codons
117
What initiates transcription and translation in the trp operon?
Simultaneous process
118
What does the ribosome reach during attenuation?
Attenuator sequence
119
What does the attenuator sequence code for?
Two tryptophan amino acids
120
What does the attenuator sequence code for?
Two tryptophan amino acids
121
What binds tryptophan amino acids in the cell?
tRNA
122
Where is tRNA-bound tryptophan delivered?
To the ribosome
123
What forms in the mRNA due to tryptophan incorporation?
Terminator hairpin loop
124
What does the terminator hairpin loop cause?
mRNA dissociation from DNA template
125
What happens to RNA polymerase during termination?
Detaches from DNA
126
What is prevented when tryptophan levels are high?
Transcription of structural genes for tryptophan synthesis
127
What begins simultaneously in low tryptophan conditions?
Transcription and translation of the trp operon
128
What happens to the ribosome in low tryptophan conditions?
Pauses at the attenuator sequence
129
What forms instead of a terminator hairpin loop in low tryptophan?
Antiterminator hairpin loop
130
What does the antiterminator hairpin loop prevent?
mRNA dissociation from template strand
131
What continues due to the antiterminator hairpin loop?
Transcription of structural genes for tryptophan synthesis
132
What is the role of the trp operon attenuation?
Regulation of gene expression based on tryptophan levels
133
What is gene regulation?
Control of gene expression, switching transcription on or off
134
What does gene expression involve?
Reading gene information to create functional products
135
What do structural genes code for?
Proteins that play a role in structure or function
136
What do regulatory genes produce?
Proteins that control the expression of other genes
137
What is a repressor protein?
Prevents gene expression by binding to the operator
138
What does an activator protein do?
Increases gene expression
139
What is the promoter?
Sequence of DNA to which RNA polymerase binds
140
What is an operator?
Region of DNA that interacts with repressor proteins
141
What is an operon?
Cluster of linked genes sharing a common promoter and operator
142
What does exocytosis involve?
Release of vesicle contents from a cell
143
What is the purpose of exocytosis?
Bulk transport of materials out of the cell
144
What is exocytosis?
The process by which contents of the vesicle are released from a cell.
145
What type of transport is exocytosis?
Bulk transport.
146
What does exocytosis allow for?
Movement of large substances such as proteins out of the cell.
147
Does exocytosis require energy?
Yes, it is a form of active transport.
148
What is the first stage of exocytosis?
A vesicle containing secretory products is transported to the plasma membrane.
149
What happens in the second stage of exocytosis?
The membrane of the vesicle fuses with the plasma membrane.
150
What occurs in the third stage of exocytosis?
The secretory products are released from the cell into the extracellular environment.
151
What facilitates exocytosis?
The fluid nature of the plasma membrane.
152
What can exocytosis eliminate?
Waste, preventing toxin build-up in cells.
153
What is bulk transport?
A type of active transport that uses vesicles to move large molecules.
154
What is active transport?
The movement of molecules across a semipermeable membrane requiring energy input.
155
What organelles are involved in the protein secretory pathway?
Ribosomes, rough endoplasmic reticulum, Golgi apparatus, transport and secretory vesicles.
156
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