Unit 4

Question 1

The two stages of protein synthesis in order

Answer 1

transcription and translation

Question 2

DNA to mRNA

Answer 2

Transcription

Question 3

mRNA to protein

Answer 3

Translation

Question 4

Steps of Transcription

Answer 4

1. DNA unzips (with RNA polymerase) so it can be used as a template to make mRNA
2. RNA polymerase adds nucleotides (using complementary base pairing) to the mRNA
3. mRNA breaks off and the DNA zips back together, mRNA leaves the nucleus to look for a ribosome

Question 5

Steps of Translation

Answer 5

1.The ribosome reads mRNA and finds the start codon (AUG).

2. A tRNA molecule with a complementary anticodon drops off an amino acid.
3. This continues at each mRNA codon, with the tRNA complimentary base pairing and dropping of its amino acid. The amino acids bond together making a polypeptide chain or protein.
4. This process repeats over and over until the ribosome reaches a STOP codon.

Question 6

three-nucleotide sequence on messenger RNA that codes for a single amino acid

Answer 6

codon

Question 7

AUG (methionine)

Answer 7

start codon

Question 8

UAA, UGA, UAG

Answer 8

stop codons are

Question 9

Gene expression

Answer 9

DNA -> mRNA -> Protein -> trait

Question 10

Site of replication in eukaryotes

Answer 10

nucleus

Question 11

The site of translation

Answer 11

cytoplasm and ribosomes

Question 12

point mutation in which one nitrogeneous base (nucleotide) is changed to another

Answer 12

substitution mutation

Question 13

a mutation in which a nucleotide is added to a DNA sequence in a gene

Answer 13

insertion mutation

Question 14

a mutation in which a nucleotide is removed from a DNA sequence in a gene

Answer 14

deletion mutation

Question 15

point mutation

Answer 15

a mutation affecting only one or very few nucleotides in a gene sequence.

Question 16

frameshift mutation

Answer 16

mutation that involves the insertion or deletion of a nucleotide in the DNA sequence; all of the nucleotides are shifted after the change

Question 17

Why are cells so small?

Answer 17

smaller cells are more efficient because they have more surface area across which to pass oxygen, nutrients and waste materials

Question 18

3 parts of a nucleotide are

Answer 18

sugar, phosphate, nitrogen base

Question 19

The structure of a DNA molecule can be described as a…

Answer 19

Double stranded helix, 2 strands of nucleotides: phosphate group and sugar (deoxyribose) form the “backbone”, and the nitrogenous bases (A-T, C-G) form the “rungs” of the ladder, weak hydrogen bonds hold the 2 nitrogen bases together

Question 20

Rule of complementary base pairing

Answer 20

A and T form a base pair and C and G form a base pair

Question 21

Why does DNA replicate?

Answer 21

for cellular division: reproduce, growth, and repair

Question 22

The process in which DNA makes a duplicate copy of itself. (DNA to DNA)

Answer 22

DNA replication

Question 23

Step one of DNA replication

Answer 23

DNA is unzipped by enzyme DNA helicase

Question 24

Step two of DNA replication

Answer 24

Free-floating nucleotides are joined to the original DNA strand by DNA polymerase, this builds the new strand

Question 25

End result of DNA replication

Answer 25

two identical DNA molecules are made; called: semi-conservative replication because each copy has 1 original strand and 1 new strand.

Question 26

name of DNA

Answer 26

deoxyribonucleic acid

Question 27

name of RNA

Answer 27

ribonucleic acid

Question 28

sugar of DNA

Answer 28

deoxyribose

Question 29

sugar of RNA

Answer 29

ribose

Question 30

Is RNA single or double stranded?

Answer 30

single stranded

Question 31

Is DNA single or double stranded?

Answer 31

double stranded

Question 32

Nitrogenous bases in DNA

Answer 32

Adenine, Thymine, Cytosine, Guanine

Question 33

Nitrogen base in RNA but not DNA

Answer 33

Uracil

Question 34

protein synthesis

Answer 34

the formation of proteins by using information contained in DNA and carried by mRNA