Lecture And Reading 1

Question 1

What concept is defined by dynamic equilibrium?

Answer 1

Homeostasis

Question 2

Homeostatic feedback mechanisms

Answer 2

1. Stimulus
2. Receptor
3. Control (integration) center
4. Effector

Question 3

Negative Feedback Loop

Answer 3

Reduces or switches the effect of the original stimulus to return the system back to a stable state.

Question 4

Positive feedback loop

Answer 4

Reinforces a stimulus in the same direction moving the system farther from homeostasis, until a climactic event.

Question 5

Glycolysis

Answer 5

Anaerobic process of ten sequential reactions that break glucose down into pyruvic acid molecules—- and eventually 2ATP

Question 6

Aerobic ATP production processes

Answer 6

Citric acid cycle, electron transport chain (produce 34 ATP).

Question 7

Cytosol functional activities

Answer 7

1. Enzymatic regulation of intermediary metabolism
2. Ribosomal protein synthesis
3. Storage of fat, carbohydrate, and secretory vesicles.

Question 8

Microfilament function

Answer 8

1. Contractile systems - actin/myosin
   Pinches cells in 2
2. Amoeboid- WBCs, fibroblasts, skin cells
3. Mechanical stiffeners, microvilli

Question 9

Mechanisms in maintaining homeostatic blood sugar

Answer 9

Rising blood glucose levels

1. Sensor - pancreatic beta cells - secretes insulin
2. Effectors-
   a)increased rate of glucose transport into target cell
   b) increased rate of glucose utilization and atp generation
   c)increased conversion of glucose to glycogen at the liver and skeletal muscle level
   d)Increased amino acid absorption and protein synthesis
   e) increased fat synthesis

3) Effect- glucose levels decline to homeostasis

Question 10

Anatomy of a phospholipid

Answer 10

-Polar (hydrophilic) head made up of :
Choline
Phosphate
Glycerol

-Non Polar Tails
(Hydrophobic)
Hydrocarbons

Question 11

How steroid cholesterol effects the plasma membrane

Answer 11

Higher temperatures cholesterol packs together making the membrane less fluid.

Lower temperatures more fluid

*acts as the main temperature buffer

Question 12

Major functions of membrane proteins

Answer 12

1. Transport
2. Enzymatic activity
3. Signal transduction
4. Cell-cell recognition
5. Intercellular joining (via gap junctions)
6. Attachment to cytoskeleton and extracellular matrix.

Question 13

Protein influence in membrane function

Answer 13

1. Structural support
2. Recognition
3. Communication
4. Transport

Question 14

Passive transport types

Answer 14

(No energy investment- down concentration gradient)

1. Simple diffusion
2. Facilitated diffusion
3. Osmosis

Question 15

Facilitated diffusion functional components

Answer 15

Uses a transport protein via high to low concentration.

a) channel
b) carrier

Question 16

Osmosis attributes

Answer 16

Diffusion of water across semi permeable membrane from hypotonic to hypertonic solution.

Uses aquaporins - (water protein channels, non-gated)

Shifts solvent to equalize the system.

Question 17

Osmotic pressure

Answer 17

Pressure needed to keep system in equilibrium with pure water

** the higher the concentration of solutes, the higher the osmotic pressure.

Question 18

Active transport components

Answer 18

Requires ATP, uses membrane pumps and coupled transport

Question 19

Membrane Pump

Answer 19

Carrier protein that uses ATP to move a substance across a membrane against its concentration gradient.

ex. Sodium/Potassium pump

Question 20

Physiology of sodium-potassium pump

Answer 20

1. 3 Na+ bind to cytoplasmic side of protein.
2. Phosphate is transferred from atp to protein.
3. Phosphorylation changes shape of protein and moves Na across membrane.
4. K+ binds to the protein causing phosphate release.
5. Phosphate release changes protein shape moving K+ into cytoplasm.

Question 21

Types of bulk transport

Answer 21

Exocytosis - via transport vesicles

Endocytosis- plasma membrane envelops small particles or fluid to form vesicle and enters cell.

Question 22

Endocytosis types

Answer 22

1. Phagocytosis - creates vacuole engulfing particles.
2. Pinocytosis - gulps droplets of extracellular fluid.

Question 23

Peroxisome function

Answer 23

Organelle that aids in lipid metabolism, and counteract oxidative stress and redox balance.