S3T1: Cells

Question 1

Function of cell surface membrane

Answer 1

Controls substances entering and leaving the cell (partially permeable)

Question 2

Function of rough endoplasmic reticulum

Answer 2

Transport of proteins
Folding of secondary and tertiary structure of proteins (modification of proteins)

Question 3

Function of ribosome

Answer 3

Site of protein synthesis

Question 4

Function of smooth endoplasmic reticulum

Answer 4

Site of steroid and phospholipid synthesis
Detoxification of drugs and poisons, and facilitates transport of substances within cell for export

Question 5

Function of Golgi apparatus

Answer 5

Modification of proteins within cell for storage and export out of cell

Question 6

Function of mitochondrion

Answer 6

Site of cellular respiration to release energy in the form of ATP

Question 7

Function of chloroplast

Answer 7

Site of photosynthesis
Double membrane -> inner membrane contains stroma -> flattened sacs thylakoids -> contains chlorophyll that raps light and photosynthesizes

Question 8

Function of cytoplasm

Answer 8

Site of cellular reactions

Question 9

Function of nucleus

Answer 9

Controls cell activities
Has nuclear envelope, nucleoplasm, nucleolus

Question 10

Function of vacuole

Answer 10

Storage of organic and inorganic substances
Isolate harmful materials to cell
Maintain turgor pressure in plant cells

Question 11

Function of cell wall

Answer 11

Provide tensile strength (prevent cells from bursting due to turgor pressure)
Provides structural support and protection

Question 12

How do cells make proteins?

Answer 12

Ribosomes make proteins
RER helps to transport proteins
Vesicles pinch off RER and fuse with cis-side of GA
GA stores, packages and modifies proteins
Vesicles pinch off trans-side of GA and fuse with cell surface membrane
Contents are then released out of cell

Question 13

Root hair cell adaptations (2)

Answer 13

1. Long and narrow protrusion of epidermal cell: increases SA: Vol ratio of cell so that water and mineral salts can be efficiently absorbed from cell
2. Concentrated cell sap: lowers water potential of cell sap, allows water to enter RHC via osmosis

Question 13

Xylem adaptations (4)

Answer 13

1. Long hollow tubes formed from xylem cells laid end to end: water and mineral salts conducted continuously from roots to leaves
2. Absence of cross walls/protoplasm: water to move continuously through the lumen
3. Xylem vessels bundled together: mechanical support to plant
4. Lignin deposits on walls of xylem vessels: strengthens wall and prevents collapse of vessels