Bio Biochem

Question 1

Liver 4 functions

Answer 1

• detox– cyt P450 oxidizes stuff
• glucose regulation
• bile
• cholesterol metabolism / FA synth

Question 2

Lipoprotein lipase

Answer 2

releases fatty acids from VLDL’s and chylomicrons in well fed state
-in adipocytes

Question 3

glycerol phosphate

Answer 3

• in glycolysis
• in TAG synthesis
• when well-fed
• in adipocytes

When starving, hormone-sensitive lipase (low insulin)

Question 4

Source of fuel

Answer 4

In well-fed:

• cardiac always uses FA
• liver can also use proteins
• everything except heart uses glucose (failing heart uses glucose)

In starvation:

• always fat except brain and RBC must use glucose
• ketone bodies for skeletal muscle and brain

Question 5

Respirometry

Answer 5

measure respiratory quotient expt’ally
RQ = CO2 produced/O2 consumed
Carbs = 1, Lipids = 0.7 (carbs make more CO2 than lipids per oxygen)
resting = 0.8, we use both simultaneously

Question 6

Basal metabolic rate

Answer 6

• Calorimeters can measure this using heat exchange
• based on age, weight, height, sex

Body mass protein/carbs same over time, water short term fluctuations, lipids long term

Question 7

Food hormones

Answer 7

• ghrelin- secreted before meal, increases appetite
• orexin further increases appetite (release triggered by ghrelin and hypoglycemia)
• leptin is secreted by fat- satiety- suppress orexin production

Question 8

Aluminum in blood- what form?

Answer 8

Al(OH)3 -poorly soluble
in acidic conditions, form Al 3+ and water (solvate), which replaces cofactors in the body and causes harm
(replace Fe3+, Fe2+, Ca2+, Mg2+)

Question 9

Phosphate in Kidneys- secreted/absorbed where?

Answer 9

PCT and DCT

Question 10

Proteins not found in urine but removed from the blood…

Answer 10

must have been destroyed (lysosome) or heavily modified (Golgi)

Question 11

Cell-connections

Answer 11

Hemidesmosomes: skin (attach to ECM)

Desmosomes: attach to adjacent cells exposed to mechanical stress; strong attachment; stomach, heart, bladder

Plasmodesmata: plants, algae

Gap junctions: Kind of everywhere

Tight junctions: Kidney (PCT, DCT, CD), BBB, Part of bile duct traversing liver

Question 12

Kidney

Answer 12

PCT- most reabsorption, non-ionic secretion
DCT, CD- concentrate urine
DCT- also ion conc, acid/base balance
LoH- Vasa recta exchange, adjust urine [solute]

Question 13

Respiratory cilia

Answer 13

• mucus elevator- clears pathogens, prevents obstruction of hardened mucus as in COPD
• nonmotile cilia help w/ cough reflex
• no cilia in alveoli

Question 14

Blood vessel production

Answer 14

angiopoietin + VEGF (platelet-derived)

Question 15

Ectoderm, Mesoderm

Answer 15

Ecto- Nervous system including axons

Meso- Blood, smooth muscles, endothelial cells, arteries

Question 16

Capillaries

Answer 16

do NOT have muscle contraction

• primary site of gas exchange
• endothelial turnover when injury/age
• low pressure flow

Question 17

Heterozygous advantage

Answer 17

• sickle cell anemia- malaria protection
• retinoblastoma- enhanced neural growth/neural plasticity in early life

Explains the continued presence of recessive alleles that lead to disease

Question 18

Genetic drift

Answer 18

• small populations

- eliminates minor variants

Question 19

Prenatal Karyotyping

Answer 19

will NOT tell you what allele is present on the chromosome

Question 20

Hybrid vigor

Answer 20

• does NOT apply to humans

- it’s from breeding 2 different species and having viable offspring (although they are generally infertile)

Question 21

Know the structure of ceramide and phosphocholine, a sphingomyelin (or PE)

Answer 21

https://en.wikipedia.org/wiki/Sphingomyelin

Question 22

ATP Synthesis

Answer 22

• constant H+ gradient = Cellular respiration

- dissipate gradient = glycolysis, fermentation make ATP

Question 23

Aspartate transaminase catalyzes what rxn?

Answer 23

Asp + a-ketoglutarate -> glu + oxaloacetate

(Asp -> oxalo, a-keto -> glu)

https://aaltoscientific.com/wp-content/uploads/2015/06/aspartate-transaminase1.jpg

Question 24

Red hair or Green eyes

Answer 24

polygenic inheritance

-unmasking at blond hair

Question 25

Cardiac output

Answer 25

amount of blood pumped out of heart per unit time

Question 26

AaBbCc x AaBbCc = AABBCC probability?

Answer 26

Law of independent assortment

1/41/41/4 = 1/64

Question 27

Muscles involved in walking

Answer 27

slow-oxidative
aerobic, resistant to fatigue
*see mamm phys muscle notes

Question 28

Protein misfolding

Answer 28

• likely tertiary structure
• only quaternary if they specify there’s more than 1 subunit

-primary and secondary protein structure issues tend to come from gene mutations or translational errors

Question 29

AchR

Answer 29

nAChR at neuromuscular junctions
mAChR at CNS and post-synaptic PNS

AChE receptors in all places

Question 30

Bacteria…

Answer 30

do not do meiosis or mitosis
they do binary fission
they do not transfer whole genomes through conjugation; only plasmids or transposons

bacteria attach new DNA to` part of cell membrane during binary fission

Question 31

Meselson-Stahl Expt

Answer 31

heavy nitrogen

semiconservative

Question 32

gel electrophoresis

Answer 32

separates molecules by charge or size, not density

=won’t work w/ Meselson Stahl (mass, Density)

Question 33

Lack of oxygen

Answer 33

cells release protons to make Hb release more oxygen

Question 34

Connexin

Answer 34

gap junctions

Question 35

Tight junctions

Answer 35

decrease ECF

Question 36

What excretes water?

Answer 36

aquaporins

Question 37

Hemidesmosomes

Answer 37

skin

attach epithelial cells to basement membrane