Eukaryotic Cell Structure

Question 1

What is the nucleus made up of?

Answer 1

Nucleolus
Nuclear pores
Chromatin
Nuclear envelope

Question 2

Function of Nucleus

Answer 2

Act as control centre of cell through mRNA and tRNA production
Retain genetic information
Manufacture RNA

Question 3

Parts and purpose of mitochondria

Answer 3

Cristae- Inner membrane folded to produce large SA, allow enzyme and protein attachment
Matrix - Contains protein lipids ribosomes and DNA, allows chemical reactions to occur

Overall purpose - Production of ATP

Question 4

Chloroplast Features and purpose

Answer 4

Chloroplast envelope - Selective membrane
Grana- made of 100 THYLAKOIDS which contain chlorophyll
Stroma - where synthesis of sugars occur during photosynthesis

Question 5

Types of Endoplasmic reticulum

Answer 5

Rough ED - large SA for synthesis of protein and glycoprotein, provide pathways for material transport
Smooth ED - Synthesise, store and transport lipids and carbs

Question 6

Function of the golgi body

Answer 6

Add carbs to proteins -> glycoproteins
Produce secretory enzymes
Secrete carbs
Transport modify and store lipids
form lysosomes

Question 7

Lysosomes

Answer 7

contain digestive enzymes
hydrolyse phagocytice cells
exocytosis ( release enzymes out of cell to destroy surrounding material)
Recycle organelles
Autolysis (break down organelles completely)

Question 8

Ribosomes

Answer 8

80S - found in eukaryotic cells, 25nm
70S - found in prokaryotic, mitochondria and chloroplasts, slightly smaller

Site of proteinsynthesis

Question 9

Cell wall

Answer 9

Made of polysaccharides
Provide mechanical strength
Fungi cell walls are called CHITIN

Question 10

Vacuoles

Answer 10

Has membrane called tonoplast
Contains solution of mineral salts, amino acids, wastes and sometimes pigments
Make cells turgid
Can be food store
Can attract insects to pollinate

Question 11

What is the process performed in order to study cells?

Answer 11

Cell fractionation

Question 12

What are the stages to cell fractionation?

Answer 12

Homogenisation

Ultracentrifugation

Question 13

What occurs during Homogenisation?

Answer 13

Cells are broken up using a homogeniser
Cell organelles are released
Homogenate is filtered to seperate complete cells and debris from organelles

Question 14

What occurs during ultracentrifugation

Answer 14

Filtrate spun at slow speed in centrifuge
Heaviest organelle falls to bottom
Sediment and supernatant separated
Supernatant spun at slightly faster speed

Question 15

What are the top 3 heaviest cell organelles

Answer 15

Nucleus
Chloroplast
Mitochondria

Question 16

What must happen to the cells before cell fractionation

Answer 16

Placed in a solution which is
Buffered - Prevent Ph altering cell organelles
Isotonic - prevent shrinking or bursting of cell organelles
Cold - slow enzyme activity