Chapter 19 cellular control

Question 1

What is the definition of a mutation

Answer 1

Change in DNA base sequence caused by mutagens

Question 3

What are the different types of mutations

Answer 3

1- Point mutations

Question 4

What are point mutations

Answer 4

Affects only 1 nucleotide (base)

Question 5

What are the different types of point mutations

Answer 5

1- Subsituition
2- insertion
3-deletion

Question 6

What is a frameshift mutation and how is it caused

Answer 6

It is caused by insertion and deletion happening (point mutations)

because of I or D of a base, it will disrupt he triplet code reading (codon), this is a frameshift mutation, causes a different type of protein to be made

Question 7

What does degenerate mean?

Answer 7

Multiple codons can code for one particular amino acid meaning a point mutation may have no effect allowing us to make the same protein for normal functioning

Question 8

What are the effects of mutations

Answer 8

1- a Mutation can be “neutral or silent” = no effect, even if there was change, it is still the same amino acid, degenerate nature of the codon
2- A mutation can be “beneficial”= enhanced function of the protein (rather rare)
3- “Damaging” = malfunctioning protein made

Question 9

Types of mutations you need to be aware of

Answer 9

• “nonsense” = codon has been changed into a stop codon= shorter protein than expected, hence wouldn’t work
• “missense”= Substitution kind of, a particular amin acid has been turned to another amino acid meaning our degenerate coding has failed in that sense
  -“chromosomal mutations” where large sections of chromosomes are altered rather than individual or one to two bases

Question 10

What is translocation? CHECK

Answer 10

A section moved itself from place of one chromosome to another place, changing of locations of chromosome sections

Question 11

Transcriptional control of gene expressions

Question 12

levels of control

Answer 12

1- Transcriptional
2- Post-transcriptional
3- Translational
4- Post-translational

Question 13

What is transcriptional level of control?

Answer 13

Turning genes on and off, trying to control whether or not we allow RNA polymerase to bind to the gene to allow transcriptional to actually happen

Question 14

What is post-transcriptional level of control?

Answer 14

Editing RNA

Question 15

What is translational level of control?

Answer 15

Turning translation of and off

Question 16

What is post-translational level of control?

Answer 16

Editing protein

Question 17

What do we do in transcription?

Answer 17

Alter conditions to allow RNA polymerase to bind
Prokaryotes : Lac operon
Eukaryotes : Histone modification of chromatin remodeling

Question 18

What are histones?

Answer 18

DNA is wrapped around proteins known as histones so that it becomes compact which forms the actually structure of chromosomes of chromatin

Question 19

What is heterochromatin ?

Answer 19

When the DNA is in compact form, where it is tightly wrapped around the histone, we say that this is called heterochromatin; happens during cell division , preventing it from getting damaged…. gene is inaccessible so transcription can not happen

Question 20

What is Euchromatin?

Answer 20

loosely wound DNA in interphase, gene becomes accessible, transcription can happen

Question 21

What happens in Interphase?

Answer 21

When protein synthesis can happen o prepare the cell to divide

Question 22

What are