Exam 3

Question 1

Shortly after ingesting a big plate of carbohydrate-rich pasta, you measure your blood’s hormone levels. What results would you expect, compared to before the meal?

Answer 1

Insulin after, GLucagon before

Question 2

Why are proteolytic enzymes such as pepsin and trypsin secreted in an inactive form?

Answer 2

So they don’t digest the body

Question 3

What do the secretions of the parietal cells of the stomach do?

Answer 3

Initiate the chemical digestion of protein in the stomach

Question 4

Mutations in what genes lead to transformations in the idenitity of entire body parts?

Answer 4

Homeotic Genes

Question 5

What makes each insect body segment different from another?

Answer 5

Different genes are expressed

Question 6

What does the bicoid mutant tell us about the fucntion of bicoid gene in embyogenes

Answer 6

Anterior head formation

Question 7

What happens during induction?

Answer 7

Cells move to new positions as an embryo establishes its three germ tissue layer

Question 8

Meristematic tissue cells= what in humans?

Answer 8

Embryonic stem cells

Question 9

An enzyme-linked receptor has been activated by a hormone. What is the likely downstream signaling event that transduces the signal?

Answer 9

Activation of a protein phosphorylation cascade

Question 10

Where in the cell would you expect to find the receptors: first for estrogen (a steroid) and second for epidermal growth factor (a protein)?

Answer 10

Inside the cell, cell surface

Question 11

What process uses intracellular oxygen?

Answer 11

Respiration

Question 12

If the difference in partial pressure of gas on either side of the barrier to diffusion is 0, which of these events will occur?

Answer 12

No diffusion will occur because there is no gradient (High P to low P)

Question 13

How do you calculate the Partial pressure of a gas?

Answer 13

Concentration in area x pressure(mmHg)

Question 14

What does hemoglobin binding of oxygen include?

Answer 14

Cooperative binding,
Reversibility
Fe++
Ambient partial pressure of oxygen must be low

Question 15

What is special about fetal Hemoglobin?

Answer 15

it has a higher affinity of Oxygen so moms blood doesn’t gank any of it.

Question 16

What do Regulatory cascades do?

Answer 16

Establish body plans by a cascade of gene expression.

Question 17

Genetic Regulatory cascade, describe the 6 steps of gene expression,

Answer 17

1.Morphogen from undifferentiated cells(anterior-posterior axes/ large body areas)
2.Gap Genes- Organize cells into segments for large body regions
3.Pair-Rule gene- Individual Segments
4. Segment-Polarity genes ; specificy regions in each individual segment
5. Hox Genes: Specify Structure, identity
6Effector genes finally deal with prolferation, death, movement, and interaction

Question 18

characteristics of the lac operon

Answer 18

• involved in regulating metabolism of lactose specifically… operating beta galactosidase at lacZ and lactose permease at lacY (transports lactose into cell)

Question 19

Beta-galactocidase

Answer 19

-cleaves lactose into glucose and galactose , expressed by lacZ

Question 20

ara operon

Answer 20

Positive and negative control from an activator protein, arabinose,

Question 21

lac operator

Answer 21

immediately downstream of lac operon promoter

Question 22

Is the lac operon under positive or negative control and what involvement does the lacl gene have?

Answer 22

Negative control, it is actively turned off in the absence of lactose.
lacl is a repressor that when transcripted keeps lac operon from being acrivated, it is the negative controller

Question 23

How does the lacl negative controller get relieved ?

Answer 23

when lactose is present it binds to the repressor protein encodedby lacl and causes a conformational change that releases the repressor protein from the operator site.

Question 24

Arabinose present

Answer 24

Activator protein arabinose causes Transcription of ara operon , positive regulation of the ARA operon

Question 25

Ara C protein and Arabinose

Answer 25

AraC is activator in presence of arabinose

repressor in the absence of arabinose

Question 26

How is the ara operon under positive and negative control by the Ara c protein

Answer 26

AraC dimer binds to the operator and the initiator when arabinose is absent but when arabinose is present it binds to the arabinose iniator and recruits polymerase to the arabad promoter

Question 27

dissociation constant k

Answer 27

it is the concentration of ligand when 1/2 the receptors are bound, inversely related to ligand binding affinity

Question 28

what gets activated and stops in the phosphorylation cascade triggered by RTK

Answer 28

different protein kinases get triggered utilizing ATP all the way down to catalyze a series of reactions, this can thius be stopped by phosphatase

Question 29

What is pattern formation

Answer 29

Events that determine the spatial organization of cells in an embryo

Question 30

What is FISH

Answer 30

fluorescent tagging to track bicoid in drosophila

Question 31

what did volhard and wolfhauss do

Answer 31

used in situ(in place) hybridization to find where bicoid mRNA’s are located

Question 32

What is a tool-kit gene and give an example

Answer 32

a gene that encode for a variety of functions

the WNT gene in drosophila

Question 33

What are master regulators for gene differentiation

Answer 33

a cell that regulate differentiaion for a wide range of a specialized cell type

e.g MyoD is a master reguator of muscle differentiation( found by weinstraub

Question 34

explain the pulmonary system

Answer 34

pumps deoxygenated blood that returned form the systemic blood system to the lungs and back

RIght Ventricle pumps the returned doexygenated blood into the lungs then Left atrium

Question 35

EXplain the systemic system

Answer 35

freshly oxygenated blood gets pumped by the LEFT VENTRICLE to the tissues , then returns into the RIGHT ATRIUM deoxygenated throught the INFERIOR AND SUPERIOR VENA CAVA