rhe rest of tne DNA notes

Question 1

how does location of protein synthesis affect function?

Answer 1

if protein synthesis occurs at a free ribosome the protein is used by the cell. if it occurs at the rough ER, the protein is packaged by the golgi and sent outside the cell

Question 2

prokaryotic protein synthesis

Answer 2

transcription: initiation -> elongation -> termination

- no mRNA processing

Question 3

mutations

Answer 3

• can be positive, neutral, or negative based on the effect it has on phenotype
• depends a lot on environmental context
• primary source of genetic variation

Question 4

why mutations occur

Answer 4

• errors in dna replication or repair mechanisms

- external factors (radiation, reactive chemicals

Question 5

structure and function in biology involve two interesting aspects

Answer 5

• presence of necessary genetic information
• correct and timely expression of this information
• regulated by cell signaling and environment

Question 6

new or non functioning proteins

Answer 6

• controls cell products and metabolism
• change the proteins and you could get new functions that are beneficial, you could get non functioning protein that is harmful or lethal
• changes phenotype
• if inheritable, changes population

Question 7

how new or non functioning proteins can change enzymes

Answer 7

• change in enzyme reaction
• enzyme may synthesize excessive quantities of a product
• these mutations are usually toxic, disrupting the delicate balance of biomolecules needed for life

Question 8

how bacteria transmit dna

Answer 8

• horizontally (genetic info is transferred within same generation)
• transformation, transduction, conjugation
• all increase variation

Question 9

gene regulation results in

Answer 9

differential gene expression, leading to cell specialization

Question 10

small regulatory rRNAs or miRNAs

Answer 10

• can block transcription

- could be beneficial for oncogenes

Question 11

regulatory genes

Answer 11

• sequence of DNA encoding for a regulatory protein or RNA

- ex: Iac Operon most used model in prokaryotes

Question 12

transcription factors

Answer 12

• involved in gene regulation
• 100s of them
• bind to specific dna sequence and/or regulatory proteins
• some are activators and others are repressors
• can help to start transcription and helps control protein concentrations

Question 13

promoter

Answer 13

where rna polymerase attaches

Question 14

enhancer

Answer 14

sequence of dna upstream that bind transcription factors which help create a loop of dna initiating transcription

usually involve bringing enhancer next to promoter via interactions of TF and regulatory elements to start transcription

Question 15

what does gene regulation account for

Answer 15

phenotypic differences between organisms with similar genes

Question 16

signal transduction

Answer 16

mediates gene expression and cell function

Question 17

cytokines

Answer 17

control checkpoints in cell cycle

Question 18

pheromones

Answer 18

(in yeast) trigger mating gene expression

Question 19

ethylene

Answer 19

levels change production of different enzyme levels and fruit begins to ripen

Question 20

p53

Answer 20

• changes in p53 activity can result in cancer
• stress increases p53 levels
• p53 targets genes that control the list in the green box