Cell structure + Movement of molecules

Question 1

What are the levels of organisation?

Answer 1

1. Organelles
2. Cells
3. Tissues
4. Organs + Organ systems

Question 2

What is the function of a NUCLEUS?

Answer 2

Membrane - bound organelle containing genetic material.

Question 3

What is the function of CYTOPLASM?

Answer 3

Material that fills the cell to facilitate chemical reactions and hold organelles in place.

Question 4

What is the function of a CELL MEMBRANE?

Answer 4

Phospholipid bilayer that controls movement of substances into and out of the cell.

Question 5

What is the function of a CELL WALL?

Answer 5

External to cell membrane that protects + mantains the shape of cell.

Question 6

What is the function of MITOCHONDRIA?

Answer 6

Carry out cellular respiration

Question 7

What is the function of CHLOROPLASTS?

Answer 7

Carry out photosynthesis.

Question 8

What is the function of RIBOSOMES?

Answer 8

Site of protein synthesis.

Question 9

What is the function of a VACUOLE?

Answer 9

Storage organelle in plants to store water + dissolved substances.

Question 10

Similarities + differences between animal and plant cells

Answer 10

Similarities: cell membrane, nucleus, cytoplasm, ribosomes, mitochondria
Differences: cell wall, vacuole, chloroplasts

Question 11

What is the definition of diffusion?

Answer 11

• It is the net movement of particles moving from a high concentration to a low concentration.
• Random movement of particles meaning its a passive process and requires no energy.

Question 12

What is a concentration gradient?

Answer 12

Difference of concentration between two areas

Question 13

What is osmosis?

Answer 13

• Movement of water particles from a high concentration of water molecules to a low concentration of water molecules through A PERMEABLE MEMBRANE.

Question 14

What is active transport?

Answer 14

-Movement of molecules from a low concentration to a high concentration (AGAINST THE CONCENTRATION GRADIENT).
Through a carrier protein using energy from respiration.

Question 15

For what is active transport used?

Answer 15

Used to continue transport of small amounts of remaining nutrients against concentration gradient.

Question 16

Where does active transport take place?

Answer 16

Small intestine (uptake of glucose)
Root hair cells (uptake of ions from soil water)
Plant (uptake of ions from soil water)

Question 17

For what is energy required in active transport?

Answer 17

To change the shape of the carrier protein.

Question 18

Describe process of active transport

Answer 18

1. Low concentration outside cell + high concentration inside cell.
2. Carrier protein uses energy from respiration to change its shape, moving substance into cell.
3. Substance moved into cell against concentration gradient + carrier molecule uses energy supplied from repiration to drive movement across cell membrane.
4. Molecule is then released into cell.

Question 19

How is the energy in active transport sometimes called?

Answer 19

ATP - (energy created by respiration)

Question 20

What are the factors that affect the rate of movement of substances into and out of cells?

Answer 20

DISTANCE TRAVELLED - greater distance = slower rate of diffusion.
CONCENTRATION GRADIENT - greater difference in concentration = faster the diffusion.
MASS OF MOLECULES - heavier the molecules = move slower, slower rate of diffusion (+ viceversa)
TEMPERATURE - higher temperature = increases energy therefore movement of molecule increases at rate of diffusion.