Ch 4- Physiology Of Cells

Question 1

Active transport

Answer 1

Movement that requires energy (ATP) from the cell. “Uphill” Moves from low concentration to high concentration.

Question 2

Passive transport

Answer 2

Movement that does not require energy from the cell. Molecules use their own energy. “Downhill”. High to low concentration.

Question 3

Enzyme

Answer 3

Functional proteins. Catalysts that speed up chemical reactions.

Question 4

Substrate

Answer 4

Is the substance a specific enzyme acts on. Most enzymes act on only one substrate.

Question 5

Metabolism

Answer 5

Anabolic and catabolic reactions. All the chemical reactions going on in the body.

Question 6

Diffusion

Answer 6

Passive transport. Tendency of small molecules to spread out evenly in a given space. “Down the concentration gradient.”

Question 7

Dialysis

Answer 7

Passive transport. The separation of smaller (diffusible) particles from larger (not diffusible) particles through a semipermeable membrane.

Question 8

Osmosis

Answer 8

Passive transport. Diffusion of water through a selectively permeable membrane. From high to low concentration gradient.

Question 9

Facilitated diffusion

Answer 9

Diffusion through carrier proteins in cell membranes. Use carrier molecules, no energy. From high to low concentration. Faster than any other types of diffusion. Passive transport.

Question 10

Filtration

Answer 10

Water and permeable so lutes move through a membrane due to hydrostatic pressure.

Question 11

Isotonic solution

Answer 11

Same water concentration on both sides of the membrane. Cell stays the same.

Question 12

Hypotonic solution

Answer 12

Solutions that cause a cell to swell and even burst due to intake of water.

Question 13

Hypertonic solution

Answer 13

Solutions that cause a cell to shrivel or shrink due to loss of water.

Question 14

Active transport carrier mechanisms

Answer 14

Membrane transporters or membrane pumps move molecules against the concentration gradient. Examples: calcium pumps in muscles, sodium/potassium pumps in nerves.

Question 15

Endocytosis

Answer 15

Engulfing large particles into the cell.

Question 16

Exocytosis

Answer 16

Expelling large particles out of the cell.

Question 17

“Lock and key” model

Answer 17

Deals with enzymes. Describes the physical fit of an active site and substrate.

Question 18

How are enzymes named?

Answer 18

…ase ending after the substrate like…lipase, protease, lactase…
Some older ones have different names like pepsin and trypsin.
They may also be in general groups according to the types of reactions they speed up like digestive enzymes and hydroplanes.

Question 19

Allosteric effectors

Answer 19

Activate or inhibit enzymes by changing their shape.

Examples: pH, temperature, drugs, other control molecules, cofactors like some vitamins.

Question 20

Describe the importance of enzymes in metabolic pathways.

Answer 20

Metabolic pathways involve many enzymes.

Question 21

Equation for cellular respiration

Answer 21

C6H12O6 + O2 —-> CO2 + H2O + energy

This is where most of our body heat comes from. We get energy in the form of 36 ATP and heat.

Question 22

Cellular respiration step 1

Answer 22

Glycolysis - anaerobic, takes place in cytoskeleton.

Glucose broken down to 2 pyruvic acid and nets 2 ATP’s and m
NADH.

Question 23

Cellular respiration step 2

Answer 23

Citric acid cycle- aerobic, takes place in the mitochondria.

Pyruvic acid enters the cycle attached to CoA….chops off CO2….releases NADH.

NADH stores high energy electrons.

Question 24

Cellular respiration step 3

Answer 24

Electron transport system. On mitochondrial membranes. Aerobic.

NADH gives up energy as it changes to NAD+.
That energy is used to make more ATP.

Question 25

Cystic fibrosis

Answer 25

Genetic disorder. (Cl pump damage)

Inherited disease involving abnormal Cl- ion transport; causes secretion of abnormally thick mucus and other problems.