chapter 4 learning objectives

Question 1

define concentration

Answer 1

a measure of the quantity of a substance contained in a specified volume of solution.

Question 2

define concentration gradient

Answer 2

gradient represents potential energy.
-difference in solute concentrations between two adjacent regions (a solute is more concentrated in one region than in a neighboring region).

Question 3

why does diffusion require a gradient?

Answer 3

because

Question 4

discuss simple diffusion

Answer 4

• form of passive transport in which a substance moves down its concentration gradient without the use of a transport protein.
• does not require energy
• moves material in the direction of a concentration gradient

Question 5

discuss osmosis

Answer 5

• is the movement of H2O into the cell membrane
• is a simple diffusion
• water diffuses from the left side (low solute concentration) toward the right side (high solute concentration).
• no protein required

Question 6

discuss facilitated diffusion

Answer 6

• form of passive transport in which a substance moves down its concentration gradient with the aid of transport proteins
• needs ATP from protein

Question 7

discuss active transport

Answer 7

movement of substances across a membrane against its concentration gradient, using a carrier protein and energy from ATP

Question 8

discuss endocytosis

Answer 8

form of transport in which the cell membrane engulfs extracellular activity
-requires energy

Question 9

discuss exocytosis

Answer 9

form of transport in which vesicles containing cell secretions fuse with cell membrane

Question 10

Define hypertonic

Answer 10

• highly concentrated solution
• water is moving out of the cell
• crentation

Question 11

Define hypotonic

Answer 11

• low concentration “dilute”
• water is moving in the cell
• lysis

Question 12

Define isotonic

Answer 12

• equal concentration

- no net gain

Question 13

Define vesicle

Answer 13

a membrane bonded sac that transports materials within a cell

Question 14

what does vesicle formation allow? a

Answer 14

vesicle formation allows very large macromolecules (such as polypeptides, polysaccharides, nucleic acids, etc) to cross membrane.

Question 15

Define “energy.”

Answer 15

the ability to do work. Work is to move matter.

Question 16

Where do molecules store energy?

Answer 16

in their chemical bonds

Question 17

energy can be converted from….

Answer 17

one form to another

Question 18

potential energy

Answer 18

stores energy available for work

Question 19

kinetic energy

Answer 19

energy in motion; energy being used to do work

Question 20

define chemical reaction

Answer 20

interaction where some bonds break and new bonds form, rearranging atoms and causing one substance to change into another

Question 21

define reactants

Answer 21

the starting material in a chemical reaction

Question 22

define products

Answer 22

result of a chemical reaction

Question 23

what is dehydration synthesis

does this require or release energy?

Answer 23

formation of covalent bond between 2 molecules by the loss of water
require energy

Question 24

hydrolysis

does this require or release energy?

Answer 24

splitting a molecule by adding water

-releasing energy

Question 25

State the full name of ATP

Answer 25

Adenosine Tri Phosphate,

Question 26

Define “metabolism”

Answer 26

the biochemical reactions of a cell

Question 27

What type of biological molecule is an enzyme?

Answer 27

protein

Question 28

Define “energy of activation’ aka ‘activation energy.

Explain how it is affected by enzymes.

Answer 28

energy required for a reaction to begin
the “push” all reactions need

enzymes reduce the amount of energy needed to complete a reaction

Question 29

Define “substrates” and “active sites.”

Answer 29

active site- the part of an enzyme to which substrates bind

substrates-the molecule that an enzymes acts on

Question 30

Explain the difference between competitive and non-competitive

Answer 30

• non competitive inhibition- change in the enzyme’s shape occurring when an inhibitor binds to a site other than the active site.
• competitive inhibition- change in the enzyme’s activity occurring when an inhibitor binds to the active site, competing with the active site’s normal substrate.

Question 31

Give examples of conversion of energy in the biological world.

Answer 31

photosynthesis and cellular respiration

photo- plants and some microbs use CO2 + H2O + to make glucose and other carbohydrates.

Question 32

what is meant by ‘oxidized”?

Answer 32

means the loss of electrons-corresponding loss of energy
releases KE
CATABOLIC AND EXERGONIC

Question 33

What is meant by “reduced”

Answer 33

gain of electrons (and their energy)
transfer of electrons
require KE
ANABOLIC AND ENDERGONIC reactions

Question 34

Why is ATP so important? Why do we need it? Clearly state the function of ATP.

Answer 34

ATP is a type of nucleotide. All cells depend on the potential energy of ATP to power their activities. ATP is used in all cells to perform chemical reactions to do different kinds of work.The function is to power many biological processes by its high energy phosphate bonds.

Question 35

Explain why enzymes are specific – why they only work on one set of substrates.

Answer 35

enzyme’s active site have a specific shape.