Before Midterm

Question 1

What is comparative animal physiology?

Answer 1

Animal physiology is the study of how animals function at all levels of organization.

Question 2

What is the August Krogh principle?

Answer 2

There is an optimally suited animal to study most biological problems.

Question 3

What is homeostasis?

Answer 3

Homeostasis is a tendency for an animal to maintain relative internal stability in the face of external fluctuation

Question 4

How is homeostasis possible?

Answer 4

Regulatory systems

Question 5

What are the benefits of conformity?

Answer 5

No cost associated

Question 6

How does negative feedback work?

Answer 6

Negative feedback control systems regulate a variable by opposing its deviation from a set point thereby keeping that variable within its homeostatic range.

Question 7

What do beta cells do?

Answer 7

The beta cells monitor blood glucose and release a hormone called insulin into circulation

Question 8

What do alpha cells do?

Answer 8

The alpha cells produce a hormone called glucagon

Question 9

What are most physiological variables regulated by?

Answer 9

Negative feedback

Question 10

How does positive feedback work?

Answer 10

Positive feedback control systems regulate a non-homeostatic change and that create a rapid change away from that set point and as a result of this promoting an explosive response that is unidirectional.

Question 11

What are efferent sensory neurons?

Answer 11

neurons that project towards the central nervous system

Question 12

What is acclimation?

Answer 12

a process of change in response to a controlling variable in the lab

Question 13

What is acclimatization?

Answer 13

a process of change in response to a change in a natural environmental variation

Question 14

What is adaption?

Answer 14

a chronic response to change in environmental variables through natural selection

Question 15

What does the bilayer of phospholipids in cells do?

Answer 15

bilayer of phospholipids separates the intracellular from the extracellular fluid

Question 16

Describe Peripheral proteins

Answer 16

• The peripheral proteins are only associated with the outer or the inner surface of the plasma membrane.
• They can be removed without destroying the membrane.

Question 17

What are proteins that are anchored to the outside of cells involved in?

Answer 17

Cell-to-cell recognition.

Question 18

Where are integral membrane proteins found?

Answer 18

across the plasma membrane

Question 19

What do integral membranes provide the mechanism for?

Answer 19

transmembrane transport

Question 20

What does the percentage of lipid to protein ratio and the protein composition vary according to?

Answer 20

The function of the cell

Question 21

Why do we call the plasma membrane a fluid mosaic?

Answer 21

• it is composed of a mixture of proteins and lipids

- both the proteins and the lipids can readily move around in the membrane

Question 22

What is the composition of cell membranes related to?

Answer 22

Their permeability

Question 23

What must molecules following the transcellular path cross?

Answer 23

both the apical layer and the basal lateral side of the cell membrane

Question 24

what must molecules passing through the paracellular path be able to move through?

Answer 24

tight junctions between cells.

Question 25

What are cells in epithelium membranes attached to one another via?

Answer 25

tight junctions

Question 26

What pathway of movement do large particles use?

Answer 26

transcellular

Question 27

What kind of composition do cell membranes have?

Answer 27

Heterogeneous

Question 28

What must the outer layers of cell membranes be capable of?

Answer 28

recognizing endocrine paracrine autocrine signals or neurotransmitters.

Question 29

what is the inner layer of the cell membrane specialized for?

Answer 29

intracellular signaling | and attachment of the cell membrane to the cytoskeleton of the cell.

Question 30

What are lipid rafts?

Answer 30

regions of the plasma membrane that accumulate cholesterol and glycolipids

Question 31

Why are lipid rafts thicker than surrounding regions in the plasma membrane?

Answer 31

the phospholipid tails of the membrane are composed of more saturated fats and therefore they are more symmetrically organized and compact

Question 32

What is the primary element of plasma membranes?

Answer 32

Phospholipids

Question 33

what is the normal state for phospholipids at physiological temperature?

Answer 33

liquid crystalline

Question 34

What type of molecules are phospholipids?

Answer 34

amphipathic

Question 35

What is the most common class of phospholipids in plasma membranes?

Answer 35

Phosphatidylcholine

Question 36

what does cholesterol do in the plasma membrane?

Answer 36

either increase or decrease fluidity

Question 37

when does cholesterol decrease membrane fluidity?

Answer 37

when interacting with the polar head

Question 38

when does cholesterol increase membrane fluidity?

Answer 38

when interacting with the nonpolar tail

Question 39

what can alter membrane fluidity?

Answer 39

- fatty acid chain length - saturation - polar head group - cholesterol

Question 40

What will you see in terms of fat composition in the Arctic?

Answer 40

- lower percentage of saturated fats | - high percentages of monounsaturated and polyunsaturated fats.

Question 41

How can materials move across a membrane?

Answer 41

through active or passive mechanisms.

Question 42

where is concentration of sodium higher?

Answer 42

outside the cell

Question 43

where is concentration of potassium higher?

Answer 43

inside the cell

Question 44

where is concentration of calcium higher?

Answer 44

outside the cell

Question 45

where is concentration of chloride higher?

Answer 45

outside the cell

Question 46

where is concentration of anionic solutes higher?

Answer 46

outside the cell

Question 47

What does Fick's law of diffusion tell us?

Answer 47

what the rate of diffusion is for any given solute across a membrane

Question 48

What happens to the the rate of diffusion of a substance across a membrane if you increase concentration gradient?

Answer 48

it increases

Question 49

What happens to the the rate of diffusion of a substance across a membrane if you increase permeability?

Answer 49

it increases

Question 50

What happens to the the rate of diffusion of a substance across a membrane if you increase molecular weight?

Answer 50

it decreases

Question 51

What happens to the the rate of diffusion of a substance across a membrane if you increase membrane thickness?

Answer 51

it decreases

Question 52

What happens to the the rate of diffusion of a substance across a membrane if you increase temperature?

Answer 52

it increases

Question 53

What is the charge in the bulk solution?

Answer 53

Neutral

Question 54

What is the charge on the inside of the cell very close to the membrane?

Answer 54

negative

Question 55

What is the charge of the extracellular fluid very close to the membrane?

Answer 55

positive

Question 56

What determines the movement of ions?

Answer 56

electrochemical gradient

Question 57

What is osmosis?

Answer 57

he diffusion of water through a semipermeable membrane from a region of low solute concentration to a region of high solid concentration

Question 58

In osmosis, when do you no longer have any water movement?

Answer 58

when hydrostatic pressure equals osmotic pressure.

Question 59

what do the effects of tonicity depend on?

Answer 59

differences in osmolarity but also on the permeability of the membrane to the solutes

Question 60

When is a solution called isotonic?

Answer 60

when the solution has no effect on cell volume

Question 61

what does osmolarity take into account?

Answer 61

total concentration of penetrating and non-penetrating solutes

Question 62

what does tonicity take into account?

Answer 62

total concentration of penetrating solutes only

Question 63

what happens if you put a red blood cell in a hypertonic solution?

Answer 63

the red blood cells will shrink

Question 64

what happens if a red blood cell is in an isotonic solution?

Answer 64

no net movement of water

Question 65

what happens if a red blood cell in is a hypotonic solution?

Answer 65

it will grow until it bursts