Biology Review

Question 1

what is the nucleus and its various functions?

Answer 1

brain of the cell, DNA storage, transcription, and ribosome assembly

Question 2

what is the ER and its various functions?

Answer 2

Synthesis of proteins and lipids; calcium storage

Question 3

where can ribosomes be found?

Answer 3

free in the cytosol or associated with the ER (secretion)

Question 4

what is the function of the golgi body?

Answer 4

post-translational modifications (every protein in secretory pathway goes through modification)

Question 5

What is the function of the cytoskeleton?

Answer 5

cell motility and mechanical tasks (involved in mechanical stability)

Question 6

what are the functions of the mitochondria?

Answer 6

ATP production (powerhouse of the cell) and apoptosis regulation (cell death)

Question 7

What are the functions of the vesicles?

Answer 7

endocytosis, exocytosis, and intracellular traffic (TRANSPORTS)

Question 8

What is the centriole responsible?

Answer 8

Assembly of the mitotic spindle

Question 9

What is the function of the lysosome?

Answer 9

Degradation of macromolecules (garbage)

Question 10

What is the central dogma?

Answer 10

DNA –> mRNA –> Protein synthesis

Question 11

What is DNA composed of (simple)?

Answer 11

phosphate head and purine/pyrimidine base (deoxi: no oxygen on carbon 2)

Question 12

What is the RNA composed of (simple)?

Answer 12

phosphate head and purine/pyrimidine base (hydroxyl group on carbon 2)?

Question 13

What are the four nitrogenous bases?

Answer 13

Adenine (A), Thymine (T), Guanine (G), and Cytosine (C)

Question 14

How many hydrogen bonds do Guanine (G) and Cytosine (C) form?

Answer 14

3

Question 15

How many hydrogen bonds do Thymine (T) and Adenine (A) form?

Answer 15

2

Question 16

True or False: Exons are coding regions

Answer 16

True: they will be translated into protein

Question 17

How are introns removed?

Answer 17

Splicing

Question 18

Name the 3 regulatory sequences:

Answer 18

Untranslated region at 5’ and 3’ end (transcribed but not translated); Promotors and Enhancers (not transcribed)

Question 19

What are promoters and enhancers responsible for?

Answer 19

Controlling timing and location of gene expression

Question 20

What do these promoters and enhancers respond to?

Answer 20

DNA binding proteins to activate gene expression

Question 21

Where are promoters typically found?

Answer 21

Usually found immediately 5’ to the gene

Question 22

Where are enhancers typically found?

Answer 22

Can be located a distance from the gene, cell and timing specific

Enhancer can fold and bind to to promoter to increase transcription

Question 23

What is the function of the RNA (single strand of nucleotides)?

Answer 23

Transcribes and transports the information encoded by DNA to generate proteins

Question 24

What are the bases of RNA?

Answer 24

Adenine (A), Guanine (G), Uracil (U), Cytosine (C)

RNA has Uracil (U) instead of Thymine (T)

Question 25

Where is the mRNA found?

Answer 25

Messenger made in the nucleus and translated in the cytoplasm

Question 26

What and where is transcription?

Answer 26

Making a message (mRNA) from the DNA and it takes place in the nucleus

Question 27

What must happen in transcription before exported into the cytoplasm?

Answer 27

The pre-mRNA must be matured after splicing

Question 28

What is the amino acid that starts gene translation?

Answer 28

AUG (methionine)

Question 29

True or False: The amino acid (UAA, UAG, or UGA) ends gene translation.

Answer 29

False: Although UAA, UAG, or UGA ends amino acid translation, it is not an amino acid

Question 30

What is alternative splicing?

Answer 30

One gene can code for multiple proteins

Question 31

What is the 5' cap?

Answer 31

Phosphate cap that protects the mRNA as it's transported from nucleus to cytosol

Question 32

What is the poly A tail?

Answer 32

50-250 adenine nucleotides added to the 3' end that stabilizes mRNA so that it doesn't degrade

Question 33

True or False: Splicing occurs in only eukaryotes

Answer 33

TRUE

Question 34

True or False: The pre mRNA must be matured in eukaryotes and prokaryotes.

Answer 34

FALSE: Only eukaryotes must mature the mRNA in the nucleus before it is translated in the cytosol with a 5' cap and poly A tail

Question 35

True or False: Ribosomes are found in eukaryotes and prokaryotes.

Answer 35

TRUE

Question 36

What is translation?

Answer 36

mRNA is translated into proteins in the cytoplasm

Question 37

What are the function of side chains?

Answer 37

Side chains dictate how the protein interacts with the cytoplasm and membranes

Question 38

What is the function of the microRNA?

Answer 38

Binds to the 3' UTR to regulate translation

Question 39

What is the purpose of the protein chaperone?

Answer 39

Helps proteins fold correctly after translation

Question 40

What directs the protein to enter the ER?

Answer 40

Hydrophobic signal sequence at N-terminus

Question 41

What makes the protein stay at the ER?

Answer 41

KDEL at the C-terminus

Question 42

What is phosphorylation?

Answer 42

Post-translational modification of a protein by removing or adding phosphate group

Question 43

Where is the phosphate added to?

Answer 43

hydroxyl side chains: serine, threonine and tyrosine

Question 44

What signals for proteins to get degraded?

Answer 44

Small protein ubiquitin

Question 45

Where does ubiquitin send the protein?

Answer 45

Proteasome to degrade the protein