Chap 7 DNA Structure and Gene Function Flashcards
(124 cards)
1
Q
What is DNA?
A
a molecule which is a type of nucleic acid
2
Q
What do cells use to store genetic information?
A
DNA
3
Q
What do cells need to produce proteins?
A
genetic information/DNA
4
Q
What are the three parts of a nucleotide?
A
phosphate group
five carbon sugar
nitrogenous base
5
Q
What are the possible nitrogenous bases for DNA?
A
Adenine
Thymine
Guanine
Cytosine
6
Q
Nucleotides form what?
A
strands of DNA
7
Q
What bonds form between nucleotides?
A
covalent
8
Q
How many strands make up each DNA molecule?
A
two
9
Q
What is the shape of DNA?
A
double helix
10
Q
DNA strands are what to each other?
A
complementary
11
Q
What bonds form between the nitrogenous bases ?
A
Hydrogen bonds
12
Q
Which nucleotides bond to each other?
A
Adenine to Thymine
Cytosine to Guanine
13
Q
What is a sequence in DNA?
A
order of the nucleotides
14
Q
What determines the sequence of each DNA strand?
A
the sequence of the one before
15
Q
DNA is packed tightly into what?
A
chromosomes
16
Q
What is an organisms genome?
A
all of the genetic material in its cells
17
Q
What is a chromosome?
A
a discrete package of DNA coiled around proteins
18
Q
What would happen if DNA were to unwind?
A
it would be too long to fit inside the cell
19
Q
Protein production starts with what?
A
DNA
20
Q
What is a gene?
A
a small region of a chromosome
21
Q
The sequence of DNA each gene does what?
A
encodes a specific protein
22
Q
What does protein production require?
A
RNA
23
Q
What is RNA?
A
a nucleic acid that participates in protein synthesis
24
Q
What are the complementary bases of RNA?
A
Adenine to Uracil
Guanine to Cytosine
25
Shape of DNA?
double stranded/double helix
26
Shape of RNA?
single stranded
27
What is the sugar in DNA?
deoxyribose (has an H)
28
What is the sugar in RNA?
ribose (has an OH)
29
What is the function of DNA?
stores RNA and protein-encoding info, transfers info to next generation os cells
30
What is the function of RNA?
carries protein-encoding info, helps make proteins, catalyzes some rxns
31
A gene is like what?
a recipe in a cookbook
32
Where are the instructions for the "recipe"
DNA
33
What determines which proteins a cell can produce?
the genome
34
What does the cell use to synthesize RNA?
DNA
35
What is the process of RNA synthesis?
transcription
36
What does RNA do?
uses its genetic info to synthesize proteins
37
What is the process of RNA protein synthesis?
translation
38
Transcription does what?
uses DNA to create RNA
39
Where does transcription take place?
nucleus
40
Transcription is like what?
opening a cookbook to a particular page and copying just the recipe for the dish
41
In transcription what determines RNA sequence?
DNA sequence
42
What happens to make RNA?
base pairings take place between RNA and DNA nucleotides
43
What are the pairing made between DNA and RNA?
```
DNA RNA
A.....................U
C.....................G
G.....................C
T......................A
```
44
Transcription does what?
builds mRNA
45
What are the steps for transcription?
initiation
elongation
termination
46
What starts transcription initiation?
RNA polymerase
47
What does RNA polymerase do?
unwinds the DNA double helix so it can bind to DNA
48
What is the beginning of the gene called?
the promoter
49
What happens in transcription elongation?
RNA polymerase synthesizes RNA
50
RNA polymerase does what in transcription elongation?
moves along the template strand, making an RNA copy
51
RNA polymerase joins what in transcription elongation?
RNA nucleotides together into a strand of RNA
52
What happens in transcription termination?
RNA polymerase reaches the end of the gene
53
What is the end of a gene called?
the terminator
54
What is complete in transcription termination?
RNA
55
What happens at the terminator?
RNA, DNA, and RNA polymerase separate from each other
56
DNA does what at the end of transcription?
becomes a double helix again
57
Overall transcription produces what?
an RNA copy of a gene
58
In translation RNA builds what?
protein
59
Describe translation
cells translate the mRNA "message" into a sequence of amino acids
60
If mRNA is like a copy of a recipe then translation is like...?
preparing the dish
61
All cells have the same what?
genetic code
62
What is a codon?
a set of three nucleotides that encode one amino acid
63
Name the codons?
Lysine
Serine
Valine
64
Translation requires what?
ribosomes
65
What are ribosomes are made of what?
proteins and rRNA
66
What do ribosomes do?
help the three types if RNA interact with each other to build a protein
67
Each ribosome has how many parts?
two: small subunit
| large subunit
68
Translation takes place in how many steps?
3
69
What are the steps of translation?
initiation
elongation
termination
70
Describe the process of translation.
mRNA, tRNA, and ribosomes come together, link amino acids into a chain, and then dissociate again
71
What happens in translation initiation?
mRNA binds to the small ribosomal subunit
72
What happens in translation elongation?
amino acids are joined together.
73
How are amino acids joined together in translation elongation?
enzymes in the large ribosomal subunit join the amino acids together by forming a peptide bond
74
After amino acids are joined what happens next in translation elongation?
ribosome moves to the next codon
75
At each mRNA codon what happens?
the elongation process repeats (the next tRNA enters the ribosome, and it anticodon base-pairs with the mRNA codon)
76
Enzymes form what to join the new amino acids?
peptide bond
77
What is the end of the mRNA
the stop codon
78
What happens in translation termination?
a protein (release factor) binds to the stop codon. There is no tRNA that can bind there, so no more amino acids will be added.
79
Cells do what with their genes?
express
80
What is gene expression?
synthesizing RNA and then protein
81
Cells only express which genes?
the ones they need to use e.g. red blood cells express hemoglobin, pancreas cells express insulin
82
Cells regulate what?
gene expression (but in different ways)
83
How do cells save energy?
by only producing the needed proteins
84
All cells have ways to control the rate and timing of what?
transcription
85
Eukaryotic cells often control the rate and timing of what?
translation
86
What regulates gene expression?
```
DNA packaging
Transcription factors
RNA processing
RNA export
DNA degradation
Protein activity
```
87
Where does gene regulation start in eukaryotes?
the nucleus
88
How would a gene not be able to be transcribed?
by being wound up very tightly
89
What do transcription factors bind to?
DNA
90
What is affected when transcription factors bind to DNA?
the activity of RNA polymerase, altering the rate of transcription
91
What is RNA processing?
parts if mRNA can be cut out before is leaves the nucleus creating different proteins from the same mRNA
92
Certain eukaryotic proteins hold mRNA where?
inside the nucleus preventing them from reaching a ribosome
93
RNA export is what?
when a protein holds mRNA inside the nucleus
94
mRNAs may be quickly what before they can be translated into much protein?
degraded
95
While some mRNAs are quickly degraded other are...?
long lived and are translated into a lot of protein
96
What is protein activity?
the fact that some proteins are more stable while others are degraded quickly
97
In order to function proteins must...?
be properly folded
reach their correct cellular location
98
Mutations do what?
change DNA
99
What is a mutation?
a change in the nucleotide sequence of a cell's DNA
100
Some mutations can cause what?
disease
| e.g. sickle cell disease
101
What causes mutations?
spontaneously from errors in DNA replication
by mutagens
102
What are mutagens?
external agents that change DNA structure
103
What are some examples of mutagens?
Chemical
Radiation
X-rays
104
Are most mutations harmful?
No
105
Can mutations increase an individual's reproductive success?
Yes
106
Viruses can bring what into cells?
new genes
107
What happens if a cell receives a new gene?
it can produce a new set of proteins
108
How are viruses different than cells?
they are smaller and simpler
109
Viruses do not have what?
```
nucleus
organelles
ribosomes
cell membrane
cytoplasm
```
110
How do viruses get in/on a cell?
they attach to cells (they grab onto proteins on the host cell)
111
What do viruses do when in/on a cell?
inject their genes into the cell (viral DNA or RNA)
112
What happens when a virus injects it genes into a cell?
the cell begins to synthesize the viral nucleic acids and proteins
113
When the cells produce the new viral proteins what happens?
the cells produce new viruses (the nucleic acids and proteins are assembled into complete viruses and leave the cell_
114
How long can some animal viruses linger?
years
115
What prevents viral infections?
vaccines
116
What do vaccines do?
"teach" your immune system to recognize a virus and eliminate it from the body before many cells are infected
117
What are the most potent weapon against many viral diseases?
vaccines
118
What slows viral replication?
antiviral drugs
119
What do antiviral drugs do?
stop viruses from binding to cells or blocks them from hijacking transcription and translation in cells
120
Why is it difficult produce drugs with long-term effectiveness?
because viruses mutate rapidly and are so diverse genetically
121
What is tRNA?
transfer RNA
122
tRNA has codons or anticodons?
anticodons
123
mRNA has codons or anticodons?
codons
124
Anticodons have which nucleotides?
Adenine
Guanine
Uracil
(only has 3)
