Exam 2 Review

Question 1

Describe a Fluid Mosaic Model

Answer 1

Membrane is a mosaic of protein molecultes embedded in a fluid bilayer of phospholipids

Question 2

What are the 4 components of cellular membranes

Answer 2

1. Phospholipid Bilayer ( flexible matrix, animal = cholesterol, plants = sterols/no cholesterol)
2. Transmembrane Proteins (integral)
3. Interior Protein Network (peripheral or intracellular, reinforces shape)
4. Cell-Surface Markers

Question 3

Phospholipids are _____ molecules, containing hydrophobic and hydrophillic regions

Answer 3

amphipathic

Question 4

What are the 6 types of membrane proteins?

Answer 4

1. Transporter
2. Enzyme
3. Cell-surface marker
4. Cellular receptors
5. Cell to cell adhesion
6. Cytoskeleton anchor

Question 5

Describe the permeability of the lipid bilayer; what crosses and what does not?

Answer 5

Hydrophobic molecules cross easily

Polar molecules do not.

Question 6

Passive transport is movement of molecules through the membrane in which…

Answer 6

No energy is required.

Molecules move in repsonse to a concentration gradient. (diffusion)

Question 7

Diffusion is movement of molecules from ___.

Answer 7

high concentration to low concentration

Question 8

What is the structure and function of channel proteins

Answer 8

• Allows ions to pass
• They are gated; open or closed in response to stimulus (chemical or electrical)
• 3 conditions determine direction
  ( relavtive concentration, voltage differences, gated open or closed)

Question 9

What is the structure and function of carrier protiens

Answer 9

• Help transport ions and other solutes ( sugar and amino acids)
• Requires a concentration difference across the membrane
• Must bind to the molecule they transport
• Saturation - rate of transport limited by number of transporters

Question 10

What happens to animal cell in hypotonic solution?

Answer 10

Lysed

Question 11

What happens to plant cell in hypotonic solution?

Answer 11

Turgid - normal state

Question 12

What happens to animal cell in Hypertonic solution?

Answer 12

Shriveled

Question 13

What happens to plant cell in hypertonic solution?

Answer 13

Plasmolyzed

Question 14

What happens to animals cell in isotonic solution?

Answer 14

Normal state

Question 15

What happens to plant cell in isotonic solution?

Answer 15

Flaccid

Question 16

Maintaining osmotic balance:

1. Marine organisms adjust ____ ____to match seawatter.
2. Terrestrial animals circulate ___ fluid throughout their bodies
3. Plants use ____ ____ to push the cell membrane against the cell wall to keep the cell rigid.

Answer 16

1. Internal concentration
2. Isotonic
3. Turgor Pressure

Question 17

Describe active transport.

Is ATP required?

Answer 17

Moves substances against their concentration gradients.

Requires energy; ATP.

Question 18

What are the types of carrier proteins?

Answer 18

Uniporters - moves 1 molecule
Symporters - moves 2 molecules
Anitporters - moves 2 molecules in opposite directions.
(terms can also be used to describe facilitated diffusion carrers)

Question 19

Describe Coupled transport. Does it use ATP?

Answer 19

Uses ATP indirectly
Symporter is used
Uses the energy released when a molecule moves by diffusion to supply energy to active transport of a different molecule.

Question 20

Bulk Transport-
Endocytosis is the movement of substances ___ the cell.
Exocytosis is the movement of substances ___ the cell.
Which requires energy?

Answer 20

1. Into
2. Out of
3. Exocytosis

Question 21

Name the three types of endocytosis

Answer 21

1. Phagocytosis (cellular eating)
2. Pinocytosis (cellualr drinking)
3. Receptor mediated endocytosis (specific molecules are taken in after they bind to a receptor)

Question 22

What is energy in motion?

Answer 22

Kinetic energy

Question 23

What is potential energy?

Answer 23

Stored energy (because of its location or structure)

Question 24

What is the first law of thermodynamics

Answer 24

Energy of the universe is constant

Energy can be transferred and transformed but not be created or destroyed.

Question 25

What is the second law of thermodynamics?

Answer 25

As energy increases so does disorder (entropy) increase.

Question 26

Exergonic reations ___ energy

Answer 26

release.

Question 27

Energonic reations ___ energy

Answer 27

stores

Question 28

Anabolic reactions:

Answer 28

Expend energy to build up molecules, endergonic

Question 29

Catabolic reactions:

Answer 29

Harvest energy by breaking down molecules, exergonic

Question 30

What is Phosphorylation?

Answer 30

Hydrolysis of ATP releases energy by transferring its third phosphate from ATP to some other molecule

Question 31

What is activation energy?

Answer 31

the energy needed to start a chemical reaction

Question 32

How do enzymes affect activation energy?

Answer 32

Enzymes lower activation energy therefore speeding up the process.

Question 33

What are non protein helpers to enzymes? Where does it bind?

Answer 33

cofactors bind to active sites.

Question 34

What is an organic cofactor?

Answer 34

coenzyme

Question 35

Name the 2 types of enzyme inhibitors and what they do

Answer 35

competitive - binds with the active site and noncompetitive binds with the allosteric site and changes the shape of the enzyme

Question 36

Cellular respiration can produce up to ___ ATP molecules for each glucose.

Answer 36

32

Question 37

Cellular repiration is Exergonic inputs: Out puts:

Answer 37

inputs: glucose and oxygen outputs: carbon dioxide, water and heat

Question 38

Stages of cellular respiration:

Answer 38

1. Glycolysis 2. Pyruvate Oxidation 3. Citrtic Acid Cycle 4. Oxidative Phosphorylation

Question 39

Glycolysis input and output

Answer 39

Energy investment Input: •Requires 2 ATP •4 ATP formed- substrate level phosphorylation •2 pyruvate + 2 water formed•2 NADH + 2H+ formed