Eukaryotic cells

Question 1

What does cell membrane consist of

Answer 1

Phospholipids: Hydrophilic head + 2 hydrophobic tails (refer to biomolecules) forms the lipid bilayer.
Proteins: Interspersed between phospholipids. Act as pores / channels for movement of materials

Question 2

Functions of cell membrane

Answer 2

Separate cell from environment
Permeability barrier (allows nutrients to enter and waste to exit)
Protein anchor (from previous card)

Question 3

What are the movements of substances across cell membrane

Answer 3

Diffusion (region of high conc to lower conc)
Osmosis (partially permeable membrane)
Active transport (Movement of molecules from low conc to high conc)

Only active transport need energy

Question 4

function and structure of nucleus

Answer 4

Structure: surrounded by double layer of membrane. Contains nucleolus and chromatin (DNA)

Function: Stores genetic mats of cell

Question 5

function and structure of Ribosome

Answer 5

Structure: RNA + proteins. Non-membrane bound with 2 subunits

Function: Protein synthesis

Found at rough endoplasmic reticulum or free in cytoplasm

Question 6

Structure of Rough and Smooth Endoplasmic Reticulum

Answer 6

Rough: Ribosome attached + flattened sacs + membrane bound
Smooth: Lacks ribosomes + tubular + membranebound

Question 7

Function of RER / SER

Answer 7

Rough: Synthesis of secreted proteins (Ribosomes)
Smooth: Synthesis of lipids like oils and phospholipids. Detoxification of harmful substances

Question 8

Function and structure of Golgi apparatus / body

Answer 8

Structure: Flattened stacks of interconnected membranes (shaped like wifi symbol)
Function: Involved in modification, sorting, packaging, and secretion of materials like proteins

Question 9

Protein pathway in cell

Answer 9

Ribosome -> RER -> Transport vesicle -> Golgi body -> Secretory vesicle -> cell membrane

Question 10

Function of Plant vacuole

Answer 10

Maintain high internal water pressure
Store vital chemicals / waste products
May contain colour pigments or poisons

Question 11

Structure of mitochondria

Answer 11

Surrounded by 2 membranes
A smooth outer membrane
Highly folded inner membrane (folds are called cristae)

Note: Mitochondria is plural
Mitochondrion is singular

Question 12

Function of mitochondria

Answer 12

Matrix within inner membrane contains enzymes for generating ATP and mitochondrial DNA
Releases energy via aerobic respiration

Question 13

Structure and function of chloroplast

Answer 13

Structure: surrounded by 2 membranes
Function: Carries out photosynthesis (thylakoids contain enzymes and chlorophyll for photosynthesis)