2.5 - Ultrastructure of plant cells

Question 1

Give the features of the cell wall.

Answer 1

• Made of cellulose
• Freely permeable
• Cell contents press against cell wall giving turgor pressure

Question 2

List the specialist organelles present in plant cells.

Answer 2

Vacuole

Chloroplasts

Question 3

Give the features of the vacuole.

Answer 3

• Membrane (called tonoplast) lined sac
• Contains cell sap Permanent within plant cells (transient (temporary) in animal cells).
• Tonoplast is selectively permeable.

Question 4

Give the features of chlorplast

Answer 4

• Responsible for photosynthesis
• Found in green parts of plants (leaves, stem not roots)
• Double membrane (like in mitochondria)
• Chloroplasts manufacture their own proteins as they have DNA and ribosomes

Question 5

What is the structure of a chloropolast?

Answer 5

Internal membrane network - flattened sacs called thylakoids - Several stacked thylakoids make up a granum. - Grana contains chlorophyll (site of photosynthesis) - Starch grains float in stroma (fluid inside chloroplast) - Starch produced by photosynthesis exists in starch grains - Internal chloroplast membrane has large SA, needed for enzymes proteins & pigment molecules for phootosynthesis.