Exam 1-Molecules and Cells

Question 1

proteins

Answer 1

• 10-30% of cell mass
• AA cannot be stored
• adult humans resynthesize 2-3% proteins/day
• 10% AA come newly from food

Question 2

molecular chaperones

Answer 2

deciding a protein is no longer needed, its time for it to be broken down

Question 3

heat shock (stress) proteins

Answer 3

help proteins fold when in stressful environment (CO2 levels, pH, heat)

Question 4

ubiquitous

Answer 4

everywhere; can attach to just about anything, tag it, get rid of a protein because its no longer needed

Question 5

fibrous proteins

Answer 5

actin
long, simple structure (2)
not easily broken
structural purpose

Question 6

globular proteins

Answer 6

more compact (3-4)
enzymes, dynamic
higher turnover rate
more vulnerable to denaturing

Question 7

lipids

Answer 7

temperature sensitive, energy, insulation, flotation, shock-absorption, membranes, hormones

Question 8

saturated and unsaturated lipids

Answer 8

• saturated: (all H’s) solid at room temperature

- unsaturated: liquid at room temperature (increases cell membrane fluidity in the cold)

Question 9

(lipids)

triglycerides

Answer 9

compact energy source, shock absorption, insulation, dynamic

Question 10

(lipids)

ketone bodies

Answer 10

preferentially used when glucose levels low

starvation mode

Question 11

(lipids)

sterols

Answer 11

• cholesterol and its derivatives
• membrane fluidity (stabilize membranes)
• steroid hormones
• vitamin D

Question 12

carbohydrates

Answer 12

flexible, easily stored, not temperature sensitive

Question 13

(carbohydrates)

monosaccharides

Answer 13

• glucose
• most common form of exchanged and stored cellular energy
• metabolized in Krebs

Question 14

(Carbohydrates)

starch

Answer 14

• glycogen
• animals store glucose as glycogen
• liver and skeletal muscle

Question 15

(carbohydrates)

fiber

Answer 15

• cellulose

- plant form of storable glucose

Question 16

(carbohydrates)

attached carbohydrates

Answer 16

• glycolipids (immunology)

- glycoproteins (protect from breakdown)

Question 17

cell signaling

Answer 17

signal reception

signal transduction

Question 18

ligand-gated channel

Answer 18

ligand must bind, channel, ion movement (electrical)

Question 19

G protein-coupled receptor (GPCR)

Answer 19

triggered by receptor, can now travel and set off cascade

involve activating and deactivating enzymes (effect metabolism)

Question 20

enzyme-linked receptor

Answer 20

receptor is an enzyme, dimerization, growth factors

Question 21

intracellular receptors

Answer 21

steroid (can cross lipid membranes), bind to receptor within cell