Cells

Question 1

Structure of mitochondrion

Answer 1

Has an outer membrane and an inner membrane
The inner membrane is folded to form cristae
Inside the inner membrane is a matrix containing enzymes, ribosomes and a circular DNA molecule

Question 2

Function of mitochondrion

Answer 2

The site of aerobic respiration and responsible for producing most of the ATP in a cell

Question 3

Rough endoplasmic reticulum structure

Answer 3

Flattened discs of membranes

Surface is covered in ribosomes

Question 4

Rough endoplasmic reticulum function

Answer 4

Processes proteins made by the ribosomes

Question 5

Nucleus structure

Answer 5

A large organelle enclosed by a double membrane which is perforated by pores
Contains chromosomes and one or more nucleoli

Question 6

Function of the nucleus

Answer 6

Nuclear pores are needed to allow mRNA and ribosomes to leave and enzymes to enter
Chromosomes contain DNA which controls synthesis of proteins

Question 7

Golgi apparatus structure

Answer 7

Stack of membrane bound, flattened sacs in the cytoplasm

Question 8

Golgi apparatus function

Answer 8

Receives and prepares proteins synthesised on the ER for secretion from the cell.
This often involves adding carbohydrate to the proteins to make them into glycoproteins

Question 9

Chloroplast structure

Answer 9

Surrounded by two membranes and contains a matrix called stroma which has a system of membranes running through it.
Stroma contains ribosomes, starch grains and circular DNA
Grana is stacks of thylakoids. Thylakoids hold the pigment chlorophyll.

Question 10

Chloroplast function

Answer 10

The organelle in which photosynthesis takes place. Chlorophyll pigments capture light energy and transfer it into chemical bonds

Question 11

Lysosome structure

Answer 11

Vesicles which contain hydrolytic enzymes

Question 12

Lysosome function

Answer 12

Responsible for destroying worn out organelles and digesting the contents of phagocytosis

Question 13

Vacuole structure

Answer 13

A sac bundled by a single membrane
Contains cell sap which is a solution of salts and other substances

Question 14

Vacuole function

Answer 14

Stores waste products and other substances
Changes in volume affect the turgidity of the cell

Question 15

Cell membrane structure

Answer 15

A phospholipid bilayer with extrinsic and intrinsic protein molecules

Question 16

Function of cell membrane

Answer 16

A partially permeable membrane which controls which substances enter or leave the cell

Question 17

Cell wall structure

Answer 17

Consists of cellulose microfibrils and other polysaccharides

Question 18

Cell wall function

Answer 18

Provides mechanical support and protection
Prevents the cell from bursting

Question 19

Smooth endoplasmic reticulum structure

Answer 19

Formed from continuous folds of membranes continuous with the nuclear envelope

Question 20

SER function

Answer 20

Where steroids and lipids are synthesised

Question 21

Ribosome structure

Answer 21

Very small organelle not bounded by a membrane
Consists of a large and small subunit
Made of protein and RNA

Question 22

Ribosome function

Answer 22

Uses the information in nucleic acid to synthesise proteins

Question 23

Nucleoulus function

Answer 23

Where ribosomes are produced

Question 24

What are the the 3 stages of mitosis

Answer 24

Interphase, nuclear division, cytokinesis

Question 25

What happens during interphase

Answer 25

No division takes place

Question 26

What happens during nuclear division

Answer 26

Nucleus divides into 2

Question 27

What happens during cytokenesis

Answer 27

Division of the cytoplasm

Question 28

What is the order of the stages of the cell cycle

Answer 28

Prophase, metaphase, anaphase, telophase, cytokenesis

Question 29

Prophase description

Answer 29

Chromosomes become visible because they condense Centrioles move to opposite poles Spindle fibres form from pole to pole

Question 30

Describe metaphase

Answer 30

Chromosomes are pulled to the equator of the cell via spindle fibres form Chromosomes are attached to spindle fibres via centromere

Question 31

Describe anaphase

Answer 31

Centromeres divide into two Spindle fibres pull sister chromatids apart to opposite poles Energy supplied by mitochondria

Question 32

Telophase description

Answer 32

Chromosomes have reaches their poles and become longer and thinner, and are unable to be seen by microscopes Spindle fibres break down Nuclear envelope and nucleolus reform

Question 33

Description of cytokenesis

Answer 33

Formation of a cleavage by pinching it and splitting it in two

Question 34

Describe the structure of a prokaryotic cell

Answer 34

No membrane organelles, smaller ribosomes, circular dna, cell wall that contains murein

Question 35

What structures do SOME prokaryotic cells have

Answer 35

One or more plasmid, flagella, capsule that surrounds the cell

Question 36

Describe the structure of viruses

Answer 36

Not classified as acellular but rather as having particles, capsid, attachment proteins

Question 37

What is a hypotonic solution?

Answer 37

Higher water potential outside the cell, lower water potential inside the cell. Water moves inside of the cell.

Question 38

Describe the role of phospholipids in the cell surface membrane.

Answer 38

They act as a barrier to most water-soluble substances, which ensures water soluble molecules such as sugars, amino acids and proteins cannot leak out of the cell

Question 39

What is the role of cholesterol in the cell surface membrane?

Answer 39

It regulates the fluidity of the membrane and stabilises the cell membrane at higher temperatures

Question 40

Describe the role of glycolipids and glycoproteins in the cell surface membrane

Answer 40

They act as receptor molecules, binding with certain substances at the cell’s surface

Question 41

What are the three main receptor types on the cell surface membrane

Answer 41

-signalling receptors for hormones and neurotransmitters -receptors involved in endocytosis -receptors involved in cell adhesion and stabilisation

Question 42

What is the role of transport proteins in the cell surface membrane

Answer 42

They create hydrophilic channels to allow ions and polar molecules to travel through the membrane