Lecture 4

Question 1

Enzyme action
-_________ binds to enzyme’s active site
-molecules form-enzyme substrate complex
-enzyme–substrate ________ (lock and key)

-enzyme releases reaction products
-enzyme ________ and can repeat process

enzymes _________ activation energy–> allows reaction to occur at a faster rate

Answer 1

substrate
-specificity
-unchanged
-lower

Question 2

cofactors:
coenzymes:

Answer 2

-inorganic elements (metal) (copper, magnesium, zinc) that help enzymes move along
-organic molecules (derived from vitamins) that help enhance enzyme activity

Question 3

Nucleotides
-organic compounds with three principal components:
1: ___________ (single or double ______- nitrogen ring
2: ___________ (monosaccharide)
3: one or more __________ groups

examples of nucleotides:
-________ -energy transfer

nucleotides are building blocks for ______ and ______

Answer 3

1: nitrogenous base; carbon
2: Sugar
3: phosphate

-ATP (Adenosine triphosphate)

-DNA; RNA

Question 4

Glucose + oxygen –> carbon dioxide + _______ + ______

Answer 4

H2O (water); ATP (energy)

Question 5

If there is NO oxygen….
a total of ___ ATP made per glucose molecule
since NADH is recycled

Answer 5

2

Question 6

if there is oxygen…
a net total of up to ____ ATP made per glucose molecule

Answer 6

32

Question 7

Cell Shapes and Sizes Human cell size
-most cells about ___-___ um (micrometers) in diameter
-Egg cells are 100 um diameter (YOU CAN SEE WITH NAKED EYE)

-the RBC is Mother Nature’s internal micrometer for histology labs (___-____ micrometers in diameter and about ___ micrometers thick)

Answer 7

10-15
7-8; 2

Question 8

Limits on cell size:
-an overly large cell CANNOT support itself
-______ increases faster than SA which could lead to a cell to _________

Answer 8

volume; rupture

Question 9

The Plasma membrane
-it is a compartment boundary!
-_____% of membrane molecules are lipids
-phospholipids _____%
-cholesterol _____%
-glycolipids ____ %
-___% of molecule protein (____% of weight)

Answer 9

98
75
20
5
2;50

Question 10

the plasma membrane is a lipid ________
phospholipids have…
-a _____, hydrophilic head group
-a ________, hydrophobic tail

Answer 10

bilayer
polar
non-polar

Question 11

Membrane proteins
1.
2.

Answer 11

peripheral protein (hydrophilic)
transmembrane protein (outside parts are hydrophilic; while inside is hydrophobic)

Question 12

proteins are sometimes clustered on _________- rich lipid “rafts” that are hard

keeps proteins anchored

Answer 12

cholesterol

Question 13

transmembrane proteins are often:
a.
b.
c.
d.
e.
f.

Answer 13

receptor
enzyme
channel
gated channel
cell-identity marker
cell-adhesion molecule (CAM)

Question 14

receptor transmembrane protein

Answer 14

a receptor that binds to chemical messengers such as hormones sent by other cells

Question 15

enzyme transmembrane protein

Answer 15

an enzyme that breaks down a chemical messenger and terminates its effect

Question 16

channel transmembrane protein

Answer 16

a channel protein that is constantly open and allows solutes to pass into and out of the cell

Question 17

gated channel transmembrane protein

Answer 17

a gate that opens and closes to allow solutes through only at certain times

Question 18

cell-identity marker transmembrane protein

Answer 18

a glycoprotein acting as a cell-identity marker distinguishing the body’s own cells from foreign cells

Question 19

Cell-adhesion molecule (CAM) transmembrane protein

Answer 19

a cell-adhesion molecule (CAM) that binds one cell to another

Question 20

many peripheral proteins act as _________ __________

Answer 20

second messengers

Question 21

kinase

Answer 21

adds phosphate to a protein–> activates protein–> triggers cellular response

Question 22

the glycocalyx: fuzzy coat external to plasma membrane
-involved in cell _______

Answer 22

identity

Question 23

Membrane transport:
Requires energy-
1.
2.

Does NOT require energy-
1.
2.
3.
4.

Answer 23

1. active transport
2. bulk transport (ex. endocytosis)
3. Osmosis
4. Diffusion
5. Facilitated diffusion
6. Filtration

Question 24

Filtration:
particles are driven through membrane by physical ________
-type of passive transport that relies on pressure of your _____
-blood pressure in capillary forces ____ and small _____ such as salts through narrow clefts between capillary cells

Answer 24

pressure
blood
water; solutes

Question 25

osmosis: diffusion of _____ from ____ concentration to _____ concentration

Answer 25

water; high; low

Question 26

hypotonic solution: high water concentration; low solutes–> water moves _____ the cell

hypertonic solution: low water concentration; high solutes–> water moves ______ the cell

isotonic: equal water and solute concentrations

Answer 26

into; out of

Question 27

Carrier-mediated transport
Three kinds of carriers
1.
2.
3.

Answer 27

uniport
symport
antiport

Question 28

uniport carrier

Answer 28

moves only one type of molecule in one direction

Question 29

symport

Answer 29

moves 2 different molecules in one direction

Question 30

antiport

Answer 30

moves 2 different molecules in two directions

Question 31

Three mechanisms of carrier-mediated transport:
1.
2.
3.

Answer 31

1. facilitated diffusion
2. primary active transport
3. secondary active transport