Eukaryotic Cells

Question 1

What does eukaryotic mean?

Answer 1

Cells contain a “true nucleus” surrounded by nuclear envelope and other membrane bound organelles
Contains DNA (genetic code)

Question 2

Nucleus functions (three)

Answer 2

Contains generic material (DNA in chromosomes)
Controls cell activities
Manufactures ribosomal RNA and assembles ribosomes

Question 3

Nuclear envelope functions (two)

Answer 3

Controls entry and exit of substances
Contains reactions inside the nucleus

Question 4

Nuclear pores functions (one)

Answer 4

Allows passage of large molecules such as mRNA out of nucleus

Question 5

Nucleolus function

Answer 5

rRNA manufactured and ribosomes assembled here

Question 6

What does protein bound mean?

Answer 6

The DNA is wound around proteins called histones

Question 7

What is the structure of ribosomes?

Answer 7

Small
Made up of two sub units of protein and rRNA

Question 8

What is the size of ribosomes in cytoplasm in eukaryotic cells?

Answer 8

80 s (subunits)

Question 9

What is the size of ribosomes in prokaryotic cells?

Answer 9

70 s

Question 10

Function of ribosomes

Answer 10

Site of protein synthesis

Question 11

Function of plasma membrane

Answer 11

Selectively permeable and so it regulates what can enter/leave the cell

Question 12

What is the cell theory proposed in 1839 by Schleiden and Schwann?

Answer 12

Cell is the most basic unit of life
All living organisms are composed of one or more cells
All cells arise from existing living cells

Question 13

Endoplasmic reticulum structure

Answer 13

Folded membranes (cisternae)
Rough- ribosomes on it

Question 14

Rough endoplasmic reticulum function

Answer 14

Large surface area that processes proteins from ribosomes
Pathway for transport of materials (proteins)

Question 15

Smooth endoplasmic reticulum functions

Answer 15

Synthesis, stores and transports lipids
Synthesis, stores and transports carbohydrates

Question 16

What types of cells will contain a lot of rough er?

Answer 16

Cells that need a lot of protein
e.g. Muscle, intestinal epidermis

Question 17

How many cistenae will you find in one cell?

Answer 17

Only one

Question 18

Why does there sometimes appear to be more than one cisternae?

Answer 18

If the cell is cut transfersly (cross-section) then a 2D

Question 19

Golgi apparatus structure

Answer 19

Folded membranes making cisternae

Question 20

Golgi apparatus functions

Answer 20

Adds carbohydrates to proteins to form glycoproteins
Produces secretory enzymes
Proteins processed, packaged and modified
Forms lysosomes

Question 21

Golgi vesicle structure

Answer 21

Small rounded hollow structures

Question 22

Golgi vesicle function

Answer 22

Transport substances to and from the Golgi apparatus (lipids and proteins)

Question 23

What produces lysosomes?

Answer 23

Golgi apparatus

Question 24

What size are lysosomes?

Answer 24

Medium size (up to 1um)

Question 25

Lysosomes structure

Answer 25

Bags of digestive enzymes (can contain 50 different enzymes)

Question 26

Lysosomes functions

Answer 26

Hydrolyse phagocytic cells Completely breaks down dead cells Release any useful materials that can be recycled

Question 27

Mitochondria structure

Answer 27

Double membrane, inner membrane called cristae Fluid centre called the mitochondrial matrix Loop of mitochondria DNA

Question 28

Mitochondria function

Answer 28

Site of aerobic respiration Site of ATP production

Question 29

Why do mitochondria sometimes appear to be round?

Answer 29

Orientation when cut - longitidinal / transverse

Question 30

What is respiration?

Answer 30

Release of energy from glucose

Question 31

Which molecule is used for energy in cells?

Answer 31

ATP

Question 32

Which types of cells have many mitochondria (need lots of energy)?

Answer 32

Metabolically active cells e.g. Muscle cells

Question 33

Chloroplasts structure

Answer 33

Double membrane Contains thylakoids (folded membranes embedded with pigment) Fluid filled stroma contains enzymes for photosynthesis

Question 34

Chloroplast function

Answer 34

Site of photosynthesis

Question 35

How are chloroplasts adapted for there function?

Answer 35

Grand - large surface area for attachment of chlorophyllneeded for the first stage of photosynthesis Stroma - contains enzymes for second stage of photosynthesis DNA and ribosomes - for quick synthesis of proteins for photosynthesis

Question 36

Plants have chloroplasts. Can you name another type of organism that contains chloroplasts?

Answer 36

Algae

Question 37

Vacuole structure

Answer 37

Filled with fluid surrounded by a single membrane called a tonoplast

Question 38

Vacuole functions

Answer 38

Make cells turgid and therefore provide support Temporary store of sugars and amino acids Pigments may colour petals to attract pollinators

Question 39

What cells have cell walls?

Answer 39

Plant and fungi cells

Question 40

Cell wall structure (in plants)

Answer 40

Made of cellulose microfibrils

Question 41

Cell wall function

Answer 41

Mechanical strength Allows water to more along it contributing to water movement through the pants

Question 42

What are fungi cell walls made out of?

Answer 42

Chitin, glycan and glycoproteins

Question 43

What are algae cell walls made of?

Answer 43

Cellulose and/or glycoproteins

Question 44

What is cell fractionation?

Answer 44

Cells have to be broken up and the different organelles are separated out

Question 45

What are the 4 steps of homogenisation?

Answer 45

-Tissue chopped up and placed in isotonic buffer solution at 2°to 4°C - buffered tissue in blender and blended -This breaks up the cells and leases the organellesfrom the cells -then filtered to remove complete cells

Question 46

Why does the solution have to be cold in homogenisation?

Answer 46

Reduces enzyme activity

Question 47

What are the two stages of cell fractionation?

Answer 47

Homogenisation and ultra-centrifugation

Question 48

Why is a solution of the same water potential as the tissue used in homogenisation?

Answer 48

Prevents organelles from bursting/ shrinking due to osmotic effects

Question 49

Why is the solution buffered in homogenisation?

Answer 49

Maintains a constant ph

Question 50

What is ultracentrifugation?

Answer 50

The heavy organelles will fall to the bottom first in the sediment leaving the clear supernatant which will be removed and re-spun for longer and faster