FINAL EXAM REVIEW

Question 1

The genetic code is ____ and ____. AUC and AUA codons both specify isoleucine in plants and animals

Answer 1

universal and degenerate

Question 2

How many types nucleotides do codons have

Answer 2

-4 types

singlet DNA= 4
doublet DNA= 16
triplet DNA= 64

Question 3

What is transcription and what is translation?
What is the translation machine?
What do promoters do for the transcription of mRNA?

What does a stop codon do?

Answer 3

Transcription: DNA to RNA
Translation: RNA to protein
-ribosome

-Promoter recognition by RNA polymerase essential to starting transcription

-Controls where translation ends

Question 4

What is a primary structure?
What would be an example of determining the sequence?
How would the primary structure change if last codon was UAA?

Answer 4

-the sequence of amino acids
-substitute T for U
AUG= met

-Translation would stop at UAA, last amino acid would be Glu (in A column)

Question 5

Tetracycline blocks the A site on the ribosome what does it inhibit?

Chloramphenicol blocks peptidyl transfer, what does it prevent?

Answer 5

-tRNA from binding to ribosome

-growth of the polypeptide chain

Question 6

how odes degeneracy of genetic codes make cells robust to mutations

Answer 6

-same amino acids only differ one nucleotide and are encoded by similar codons, means mutations will have little/ no effect and prevents proteins form being non functional

Question 7

What is the difference between Prokaryotes and eukaryotes?

What are cellular structures found in all cells?

Where are circular chromosomes found in plant cells?

Answer 7

-Prokaryotes are single celled, do not have similar cell structure such as nucleus, organelles, mitochondria.

-chromosomes, ribosomes, plasma membrane

-mitochondria and chloroplasts

Question 8

What are two functions of internal membranes in eukaryotic cells

Answer 8

-compartmentalization of chemical reactions
-synthesis of ATP in mitochondria

Question 9

what types of macromolecules were likely present in the first living cell?

Answer 9

phospholipids, proteins, RNA

Question 10

what are complementary DNA strand help by?
what is chromatin? How does it further mitosis?

Answer 10

-they are held by hydrogen bonds
-Is what DNA in eukaryotic cells are condensed into
-Chromatin further condenses in prophase at start of mitosis. (observable in microscope)

Question 11

three cell cycle checkpoints:

Answer 11

G1: START, nutrients available
S-G2: replication complete, damage repaired
M: Chromosomes correctly attached

Question 12

Cdk1 is positive cell regulator and RB is negative cell regulator,
how do they each control the cell cycle to ensure cell division.

Answer 12

-RB inhibits E2F to allow the cell volume to increase

-Cdk1 senses nutrients and inhibits RB when nutrients are available, producing more Cdk1

Question 13

What phase of the cell cycle has the greatest influence on progress to next phase?

Which phase are the chromosomes duplicated? When are the 2 daughter cells formed

Answer 13

G1- START- due to the availability of nutrients

-S phase
-Mphase

Question 14

What is the mitotic spindle? (meta, ana and telophases)

Answer 14

-Basically phases that segregates chromosomes during mitosis (metaphase, anaphase, and telophase)

metaphase: chromosomes line at equator
anaphase: cohesion of chromosomes pull apart into 2
telophase: formation of 2 daughter cells

Question 15

how does DNA polymerase reduce mutations during S phase?

Answer 15

“proofreading”

bubble: G-T mismatch=cannot form hydrogen bonds

pocket: replace T with C

Question 16

How is cyclin a regulator in the cell cycle

Answer 16

Cyclin associates with other cyclins during the cell cycle phases
-cyclin enforces timing of Cdk, to specific events

Question 17

What does it mean when there is either a proliferation of cells/ loss of control over cells?

What adaptation can reduce the risk of cancer?

Answer 17

there is a loss in the cell cycle checkpoint;

-decreased apoptosis= cancer
or
-loss of tumor suppressor (brakes are gone)

-extra copies of tumor suppressor genes (greenland sharks)

Question 18

What is the relationship between cancer and glycolysis?

Answer 18

-cancer uses glycolysis which produces less ATP, damages muscles.

Question 19

What is a proto-oncogene and an oncogene what happens?

Answer 19

-proto-oncogenes control rate of proliferation and are transformed into oncogenes with mutations,

=stimulates increased cell proliferation and cancer, always changing