Slide Set 2

Question 1

Proteins

Answer 1

• enzymes
• transport proteins
• form structural skeleton
• specific & variable
• structure encoded in dna

Question 2

The 2 stages of protein synthesis

Answer 2

1. Transcription (DNA-RNA)

2. Translation (RNA-protein)

Question 3

Genes are tightly coiled with histones, what removed the histone revealing promoter segment?

Answer 3

enzymes

Question 4

Transcription

Answer 4

• forms messenger RNA

- mRNA transports DNA from nucleus OUT to cytosol

Question 5

Translation

Answer 5

mRNA (in cytoplasm) > ribosome > tRNA transfers amino acids to mRNA (anticodon) > peptide bonds are joined

Question 6

1. T A C C C T C A A
2. A U G G G A G U U
3. U A C C C U C A A
4. met gly val

Answer 6

1. template strand
2. mRNA strand (U replaced T)
3. tRNA strand (U replaced T)
4. Amino acid strand

Question 7

molecular genetics

Answer 7

study of how genes are turned on and off and how they affect phenotype

Question 8

Real DNA hero

Answer 8

Rosalind Franklin, not Watson & Crick

Question 9

Where is chromatin

Answer 9

In nucleus (part of supercoiled region of chromosome)

Question 10

Nucleosome

Answer 10

• DNA + Histone proteins (H2A/H2B/H3/H4)

- repeat to make chromatin

Question 11

Genes are on or off in

• euchromatin
• heterochromatin

Answer 11

• ON

- OFF

Question 12

__ copies DNA sequence to produce mRNA

Answer 12

DNA POLYMERASE

Question 13

DNA helicase :
RNA polymerase : 
RNA nucleotides (Uracil instead of Thymine)

Answer 13

• unwinds DNA
• binds and recognises start site
• base pair with DNA
  =mRNA chain is formed

Question 14

In case of protein coding DNA, transcription is the beginning of the process that ultimately leads to _ of the genetic code (via the _ intermediate) into a function _ or _.

Answer 14

translation
mRNA
peptide
protein

Question 15

Promoter regions

Answer 15

• DNA sequences
• define where beginning of transcription begins
• are upstream or at the 5’ end of the transcription initiation site

Question 16

What binds to promoter regions?

Answer 16

TRANSCRIPTION FACTORS and RNA POLYMERASE, they initiate transcription

Question 17

Direction of transcription

Answer 17

5’—-3’ (coding strand)
3’—-5’
DNA is antiparallel

Question 18

CREM

Answer 18

cAMP response element modulator
is a transcription factor
binds to CRE in promoter region

Question 19

What doesn’t occur in absence of CREM?

Answer 19

spermiogenesis

Question 20

What are the 2 types of transcription factors

Answer 20

• gene-specific transcription factor (activate specific genes)
  ex: estrogen receptor
• general transcription factor (activate all genes)

Question 21

What are the 2 types of transcription factors

Answer 21

• gene-specific transcription factor (activate specific genes)
  ex: estrogen receptor
• general transcription factor (activate all genes)

Question 22

Alternative splicing

Answer 22

= method of processing mRNA

- enzymes clip out segment of mRNA (the introns)

Question 23

Introns vs Exons

Answer 23

Introns : noncoding segments

Exons : genes that encode protein, express

Question 24

Site of transcription

Answer 24

nucleus

Question 25

Site of translation

Answer 25

cytoplasm

Question 26

What are epigenetic mechanisms affected by?

Answer 26

``` Development Environmental chemicals Drugs, pharmaceuticals Aging DIet ```

Question 27

What is an epigenetic factor found in some dietary sources?

Answer 27

methyl group | it can activate or repress genes

Question 28

epigenetics

Answer 28

is the study of heritable phenotype changes that do not involve alterations in the DNA sequence

Question 29

housekeeping genes

Answer 29

genes always expressed in cells

Question 30

Looking for proteins by Western blot

Answer 30

CREM runs at 34Kda

Question 31

What silences a particular gene?

Answer 31

siRNA

Question 32

2 types of membrane transporters

Answer 32

- channel proteins (gated, open) | - carrier proteins (uniport, symport, antiport)

Question 33

The Na+/K+ pump shows __ active transport

Answer 33

primary | uses ATP

Question 34

The sodium/glucose pump shows __ active transport

Answer 34

secondary | uses electrochemical gradient

Question 35

Epithelia transport is either __ or

Answer 35

leaky (capillaries) | tight (kidney)

Question 36

Symptoms of cystic fibrosis

Answer 36

- chronic cough, diarrhea - runny nose - salty skin

Question 37

Pathophysiology of cystic fibrosis

Answer 37

defective epithelial ion transport

Question 38

Systems affected by cystic fibrosis

Answer 38

abnormal transport of chloride and sodium across the epithelium in all exocrine tissues (leaves thick viscous secretions in lungs, pancreas, liver, intestine). Increased salt content in sweat gland secretion

Question 39

Genetic & molecular causes of CF

Answer 39

- Faulty gene on chromosome 7 - malfunction of gene coding for CFTR (transmembrane conductance regulator), leads to defective cAMP-activated chloride and sodium channel that is present on the surface of many types of epithelial cells - NaCl trapped in the cull which pulls water in (hypertonicity) and dehydrates mucus

Question 40

How is homeostasis altered in CF

Answer 40

High levels of chloride and salt pulls water iINSIDE, causes dehydrated mucus (thick mucus is not broken down by water)

Question 41

treatments when CF

Answer 41

- antibiotics - airway clearnance therapy - bronchial dilators - vitamin supplements - enzymes to aid digestion

Question 42

Structural proteins, enzymes, membrane receptors proteins, transporters are all :

Answer 42

membrane proteins

Question 43

Endocytosis

Answer 43

The plasma membrane "traps" some extracellular marital and brings its into the cell in a vesicle

Question 44

Phagocytosis

Answer 44

- cell eating | - large particles engulfed by plasma membrane, enter in vesicle that fuses with the lysosomes

Question 45

Pinocytosis

Answer 45

- cell drinking - fluid and the substances dissolved in it enter the cell - is non selective