Lecture 10 - DNA, Transcription, and Translation

Question 1

Structure of DNA

Answer 1

phosphate sugars (backbone) made from hydrogen bonds

Question 2

any change in DNA structure/coding

Answer 2

mutation

Question 3

___ DNA actually encodes proteins

Answer 3

2%

Question 4

Code in Prokaryotes

Answer 4

1 circular molecule

Question 5

Code in Eukaryotes

Answer 5

multiple chromosomes and mitochondria and chloroplasts

Question 6

True/False: much DNA has no function

Answer 6

True

Question 7

all the genetic material in the an organism’s cell

Answer 7

genome

Question 8

human genome has _____ - _____ genes on __ pairs of chromosomes

Answer 8

20,000-25,000

23

Question 9

Gene encodes specific ____ or ___ molecule

Answer 9

protein, RNA

Question 10

Before cell divides, DNA must be ______ so each daughter cell gets the same set of genetic instruction

Answer 10

replicated

Question 11

semi-conservative

Answer 11

each new DNA strand = 1/2 old 1/2 new

Question 12

True/False: DNA replication and semi-conservative only uses a few enzymes

Answer 12

FALSE! Uses and army of enzymes

Question 13

• unwinds DNA, split

- can only work in 1 direction

Answer 13

DNA helicase

Question 14

• matches new nucleotides
• creates the polymer
• can only work in 1 direction, unlike helicase

Answer 14

DNA polymerase

Question 15

• seals broken polymers fully together through covalent bonds

Answer 15

DNA Ligase

Question 16

associates with proteins to form ribosomes, structurally support and catalyze protein synthesis

Answer 16

rRNA

Question 17

encodes amino acid sequence

Answer 17

mRNA

Question 18

binds mRNA codon on one end and amino acid on the other, linking a gene’s message to the amino acid sequence it encodes

Answer 18

tRNA

Question 19

why can we make more proteins than we have genes for

Answer 19

splicing the RNA

- each gene has multiple proteins

Question 20

5 facts of DNA replication

Answer 20

1. enzymes copy DNA simultaneously @ hundreds of origins of replication
2. proceeds in both directions @ once
3. DNA polymerase can only work @ 3’ end
   - other strand synthesized discontinuously forming okazaki fragments
4. huge amount energy required
5. very accurate but mutations do occur

Question 21

First step of gene expression

Answer 21

Transcription

Question 22

what happens in transcription

Answer 22

particular segment of DNA is copied into RNA by RNA polymerase

Question 23

1 codon =

Answer 23

1 amino acid, except for stop codon

Question 24

3 sequential nucleotides =

Answer 24

1 codon

Question 25

all mRNA codons code for amino acids except for _________

Answer 25

start codon

Question 26

2 types of mutations

Answer 26

Point

Frameshift

Question 27

affecting only one or very few nucleotides in a gene sequence

Answer 27

point mutation

Question 28

deletion or insertion in DNA sequence that shifts the way the sequence is read

Answer 28

frameshift mutation

Question 29

what type of mutation is sickle-cell anemia

Answer 29

point mutation

Question 30

universal start codon

Answer 30

AUG

Question 31

sole purpose of reproduction

Answer 31

DNA transcription

Question 32

purpose of polypeptide chain in proteins

Answer 32

RNA transcription

Question 33

• double stranded hereditary material passed on

Answer 33

DNA

Question 34

• single stranded transient/copy info and recycled

Answer 34

RNA

Question 35

copy of genes (template)

Answer 35

mRNA

Question 36

most ribosomes are where

Answer 36

rRNA

Question 37

transfers amino acids, has anticodon

Answer 37

tRNA

Question 38

find in series of nucleotides - if you have one synonymous and it changes what happens to the protein

Answer 38

nothing

Question 39

what happens if there’s an insertion or deletion of nucleotides

Answer 39

screws everything up

Question 40

why don’t we have more problems?

Answer 40

1. synonymous codon
2. certain parts of our genes (introns) get ripped out after copied ( never gets translated)
3. 2% genomes actually encodes genes