chapter 2 test

Question 1

what is the function of the cell membrane?

Answer 1

In charge of what gets in and out of the cell

Question 2

what is meant by the fluid mosaic model?

Answer 2

description of the cell membrane; has a phospholipid bilayer with embedded proteins and other functional components

• fluid = ability to move
• mosaic = different molecules

Question 3

what are the four parts of the cell membrane?

Answer 3

• phospholipids
• proteins
• cholesterol
• carbohydrates

Question 4

Describe the function of each part of the cell membrane

Answer 4

phospholipids:
- barrier between the cell and its surroundings
- holds the other components of the cell membrane

protein:
- transport specific substances across the membrane
- enzymes that speed up chemical reactions
- transmit signals from other cells

cholesterol:
- helps keep fluidity of membrane constant
- reduces fluidity of membrane at high temp
- increases fluidity of membrane at low temp

carbohydrates:
- allow other cells to recognize the cells as belonging to the body and not an intruder

Question 5

what is the difference between active and passive transport?

Answer 5

passive transport (diffusion): movement of particles across a cell membrane without the cell using energy

active transport: moves through a carrier protein
- requires ATP energy
- energy produced is used to change the shape of protein so that nutrients can be carried to the other side
- moves from low to high concentration
- moves nutrient (ex. glucose, amino acids, vitamins)

Question 6

what is an isotopic solution? what will happen to a cell if it’s put in an isotonic solution?

Answer 6

A solution that has the same solute concentration as another solution

• there is no net movement of water particles, and the overall concentration on both sides of the cell membrane remains constant

Question 7

what is an hypertonic solution? what will happen to a cell if it’s put in an isotonic solution?

Answer 7

a solution that has a higher solute concentration other than another solution
- water particles will move out of the cell, causing shrinking

Question 8

what is an hypotonic solution? what will happen to a cell if it’s put in an isotonic solution?

Answer 8

a solution that has a lower solute concentration than another solution

• water particles will move out of the cell, causing the cell to expand and eventually burst

Question 9

what is the definition of cellular respiration?

Answer 9

breakdown of a glucose molecule to make ATP so our cells can perform chemical reaction

Question 10

where does cellular respiration occur?

Answer 10

Mitohondria

Question 11

what is ATP and what is it used for?

Answer 11

provides energy for chemical reactions to take place in our bodies (cells)

Question 12

what are the three stages of cellular respiration and where do they take place?

Answer 12

Glycolysis: in a cytoplasm of a cell
Krebs cycle: in a mitochondrial matrix
Electron transport chain - in mitochondrial cristae

Question 13

what is the total ATP from one glucose molecule?

Answer 13

38

Question 14

what is lactic acid fermentation? when does it occur? what organ converts lactic acid back into glucose?

Answer 14

conversion of 2 molecules of pyruvate

happens during vigorous muscle exercise

liver converts lactic acid back into glucose

Question 15

what is alcohol fermentation?

Answer 15

• does not occur in humans
• occurs in yeast when oxygen in not available
• conversion of 2 molecules of pyruvate into ethanol

Question 16

simple diffusion definition, concentration gradient, energy required, and example

Answer 16

molecules go directly through the phospholipid bilayer

concentration gradient: high to low

energy required: no

example of molecule: small uncharged ex. co2, o2, h2o