Cell structure

Question 1

Nucleus:
What it contains?
Function
Other defining facts

Answer 1

Contains Genetic informations
DNA directs synthesis of all proteins
DNA controls all metabolic activity in the cell
Nucleus is the largest organelle
DNA is contained in a double membrane called the nucleus envelope
Nucleus pores allows molecules to move in and out of the nucleus

Question 2

Function of Nucleolus

Answer 2

Responsible for producing ribsomes

Question 3

Mitochondria:
Function
Structure

Answer 3

Site of cellular respiration
Where energy is stored as ATP
Has a double membrane inner membrane folds to form cristae
Fluid interior is called matrix
Contains small amount of DNA

Question 4

Vesicles:
Function
Structure

Answer 4

Membranous sacs that have storage and transport roles
Used to transport material in the cell
Consist of a single membrane that contains fluid

Question 5

Function of Lysosomes

Answer 5

Specialised vesicles that contains hydrolytic enzymes
They’re responsible for breaking down waste material in cells, including old organelles
Plays role in immune system, responsible for phagocystosis

Question 6

Cytoskeleton:
Structure
Function

Answer 6

Network of fibrils/fibres
Shape and stabilise the cell
Microfilaments:
formed by actin
responsible for cell movement and cell contraction during cytokinesis
Microtubules:
globular tubulin protein form tubes to make a scaffold-like structure
acts as a tract to of movement for organelle
spindle fibres are formed from microtubules
Intermediate fibres:
gives mechanical strength to cells
helps maintain their integrity

Question 7

Function and structure of Centrioles

Answer 7

a component of the cytoskeleton present in the most eukaryotic cells
composed of microtubules
forms centrosomes, involved in assembly and organisation of spindle fibres

Question 8

Endoplasmic Reticulum

Answer 8

Flattened sacs called cisternae
SER: responsible for lipid and carbohydrate synthesis and storage
RER: studded with ribosomes, responsible for synthesis and transport of proteins

Question 9

Ribosomes

Answer 9

Free-floating or on RER
no membrane
made in nucleus
made of protein and RNA
site of protein synthesis

Question 10

Golgi apparatus

Answer 10

formed of cisternae
role in modifying and packaging proteins into vesicles