Protein Synthesis

Question 1

DNA

Answer 1

(Deoxyribonucleic acid)

Nucleic acid that composed chromosomes and carries genetic info

Question 2

Chromosome

Answer 2

An enormous strand of super cooled DNA

Question 3

Genes

Answer 3

Sections of DNA on the chromosome that code for proteins

Question 4

Junk DNA

Answer 4

Noncoding sections of DNA

Question 5

Building blocks of DNA

Answer 5

Nucleotides

Question 6

3 parts of nucleotides

Answer 6

1. 5 carbon sugar (deoxyribose)
2. Phosphate group
3. Nitrogen Base (4 types)
   Adenine, guanine, thymine, cytosine

Question 7

Purines

Answer 7

Adenine and Guanine

Composed of 2 rings of nitrogen atoms

Question 8

Pyrimidines

Answer 8

Thymine and Cytosine

Composed of one ring of nitrogen atoms

Question 9

Double Helix Structure

Answer 9

Consists of 2 strands of nucleotides that form a twisted ladder

Question 10

Sugar and phosphate

Structure of DNA

Answer 10

Alternate along the sides of the ladder (linked by strong covalent bonds)

Question 11

Pair of nitrogen bases

Structure of DNA

Answer 11

Form the rungs of the ladder (linked by weak hydrogen bonds)

Question 12

Specific base pairing arrangement

Chargaffs Rule

Answer 12

A-T 2 Hydrogen bonds

C-G 3 Hydrogen bonds

Question 13

Function of DNA

Answer 13

Codes for proteins (structural proteins, enzymes, hormones)
Information for building proteins is carried in the sequence of nitrogen bases
Proteins determine physical and metabolic traits and regulate growth and development

Question 14

DNA Replication

Answer 14

Process in which DNA is copied

Question 15

Purpose of DNA replication

Answer 15

Gives daughter cells produced by cell division a complete set of genetic info identical to parent cell

Question 16

Where Replication occurs

Answer 16

Nucleus

Question 17

How replication occurs

Answer 17

Helicase enzymes unzip the parent strand by separating the nitrogen base pairs
DNA polymerase pairs free DNA nucleotides with the exposed bases on both strands following the base pair rules
Each strand from the parent molecule serve as a template
Hydrogen bonds reform spontaneously sealing the 2 strands of each DNA molecule together

Question 18

Results of replication

Answer 18

2 molecules of DNA that are identical

Each is half old (strand from parent) and half new (strand synthesized by DNA polymerase)

Question 19

RNA (Ribonucleic acid)

Answer 19

Nucleic acid involved in the synthesis of proteins

Question 20

RNA Structure

Answer 20

Composed of nucleotides but differs from DNA in 3 ways

Single strand of nucleotides instead of double stranded
Has uracil instead of thymine
Contains ribose instead of deoxyribose

Question 21

RNA function

Answer 21

3 forms of RNA involved in protein synthesis

mRNA (messenger) copies instructions in DNA and carries these to the ribosome
tRNA(transfer) carries amino acids to the ribosome
rRNA (ribosomal) composes the ribosome

Question 22

Protein synthesis

Answer 22

Cells build proteins following instructions coded in genes (DNA)
Consists of 2 parts, transcription and translation

Question 23

Transcription

Answer 23

DNA is copied into a complementary strand of mRNA

DNA cannot leave the nucleus. Proteins are made in cytoplasm. mRNA serves as a messenger and carries the protein building instructions to the ribosomes in cytoplasm

Question 24

Location of transcription

Answer 24

Nucleus

Question 25

How transcription occurs

Answer 25

RNA polymerase I twists and unzips a section of DNA (usually a single gene) from a chromosome

RNA polymerase pairs free RNA nucleotides to the exposed bases of one of the DNA strands following the base pair rules
Uracil replaces thymine
Only 1 strand of DNA serves as a template the other hangs out

Newly synthesized mRNA separates from template DNA and DNA zips back up

Question 26

Result of transcription

Answer 26

mRNA strand with instructions for building a protein that leaves the nucleus and goes to the cytoplasm

Question 27

Proteins

Answer 27

Structural and functional components of organisms
Composed of amino acids
Order of nucleotides in DNA determines order of amino acids in a protein
One gene codes for one protein

Question 28

Genetic code

Answer 28

The language that translates the sequence of nitrogen bases in DNA (mRNA) into the amino acids of a protein

Genetic code is universal to all organisms

Question 29

Codon

Answer 29

3 nucleotides on DNA or mRNA

One codon specifies one amino acid

Some codons are redundant (code for the same amino acids)

Question 30

Important Codons

Answer 30

AUG = start translation (Met)

UAA, UAG, UGA = stop translation

Question 31

Translation

Answer 31

Instructions in mRNA are used to build a protein

Question 32

Location of translation

Answer 32

Ribosome (in the cytoplasm)

Question 33

Process of translation

Answer 33

mRNA binds into a ribosome
Ribosome searches for start codon (AUG)
tRNA brings correct amino acid (methionine) to the ribosome
Each tRNA carries one type of amino acid
The anticodon (3 nitrogen bases on tRNA) must complement codon for amino acid to be added to protein chain
Ribosome reads next codon
tRNA’s continue lining up amino acids according to codons
Peptide bonds link amino acids together
Ribosome reaches STOP codon
Amino acid chain is released

Question 34

Result of translation

Answer 34

A protein