Mod 1, IQ2: How do cells coordinate activities within their internal environment and the external environment?

Question 1

Permeability

Answer 1

The ability for a molecule to pass freely through the membrane

Question 2

Two forms of transport

Answer 2

Passive: requires no energy input, down the concentration gradient

Active: requires energy (ATP), against the concentration gradient.

Question 3

Diffusion

Answer 3

Particles in a solution move from an area of high concentration to an area of low concentration

Passive process

Simple and Facilitated

Question 4

Simple diffusion vs Facilitated diffusion

Answer 4

Simple diffusion occurs when small molecules pass through the lipid bilayer of the cell membrane.

Facilitated diffusion depends on proteins to allow specific substances to pass through

Question 5

Channel proteins

Answer 5

Fastest form of transport in facilitated diffusion

Works like a gate, can be open or closed which is determined by electrical or physical signals

Question 6

Carrier proteins

Answer 6

Bind with a solute and change their shape to move the solute to the other side of the membrane.

Question 7

Osmosis

Answer 7

The movement of water molecules from a region of high water concentration to a region of low water concentration through a selectively permeable membrane.

Question 8

Active transport

Answer 8

Involves using energy in the form of ATP to transport particles across the cell membrane - always involves carrier proteins.

Question 8

Endocytosis

Answer 8

The cell takes in new materials from outside the cell by forming vesicles from infolds of the cell membrane.

Question 9

Three types of Endocytosis

Answer 9

Phagocytosis: engulfing a solid material

Pinocytosis: engulfing a liquid that contains dissolved molecules

Receptor mediated endocytosis: Engulfs specific substances determined by the receptors on the outside of the cell membrane

Question 10

Exocytosis

Answer 10

Moving molecules from the inside of the cell into the extracellular fluid

Question 11

Autotrophs

Answer 11

Make their own organic compounds from inorganic compounds found in their environment

Example: photosynthesis

Question 12

Heterotrophs

Answer 12

Gain organic compounds by eating other organisms

Question 13

Organic and Inorganic compounds

Answer 13

Organic: contain carbon and are quite complex

Inorganic: include water, oxygen, carbon dioxide, nitrogen and minerals

Question 14

Photosynthesis

Answer 14

Converts solar energy into chemical energy (glucose)

Occurs in the chloroplast - chlorophyll is used to absorb solar energy

Question 15

Photosynthesis formula

Answer 15

co2 + h2o –(Sunlight & Chlorophyll) –> c6h12o6 + o2

Question 16

Cellular respiration

Answer 16

Converts chemical energy into ATP

Question 17

Catalysts

Answer 17

An element of compound that speeds up a chemical reaction

Question 18

Biological catalysts - enzymes

Answer 18

Factors that speed up biological processes are known as enzymes

Binds with substrates to speed them up

Example: Lactase (enzyme) breaks down lactose (substrate)

Question 19

Enzyme-substrate complexes

Answer 19

Lock and key model

Induced fit model

Question 20

Lock and key model

Answer 20

If the active site does not fit correctly into the substrate, then no reaction will occur and there ill be no catalyst

Question 21

Induced fit model

Answer 21

When the substrate binds to the active site, the active site can change shape slightly to accommodate the substrate

Question 22

Catabolic reactions

Answer 22

Break down substrates into two or more parts.

Releases energy and is used to break down large molecules into smaller ones (degradation).

Question 23

Anabolic reactions

Answer 23

Build large molecules from smaller substrates.

Uses energy to build up large molecules from smaller ones (biosynthesis).