Cell Ultrastructure

Question 1

What is the nucleus surrounded by?

Answer 1

The Nuclear Envelope-A double Membrane.

Question 2

In what type of cell is a nucleus found?

Answer 2

All Eukaryotic (other than RBC)

Question 3

How is the nucleus separated from the cytoplasm?

Answer 3

A Double Membrane

Question 4

What is the size of the nucleus?

Answer 4

Relatively Large

Question 5

What does the nuclear envelope contain?

Answer 5

Pores

Question 6

What does the pores in the nuclear envelope allow?

Answer 6

Molecules (mRNA and ribosomes) to enter and leave the nucleus.

Question 7

What 2 other features does the nucleus contain?

Answer 7

Chromatin and nucleolus

Question 8

What is the nucleolus a site of?

Answer 8

Site of ribosome production.

Question 9

What is chromatin?

Answer 9

Chromosomes made of sections of linear DNA tightly wound around proteins called histones.

Question 10

What are the two types of Endoplasmic Reticulum?

Answer 10

Rough Endoplasmic Reticulum (RER)Smooth Endoplasmic Reticulum (ER)

Question 11

Which Cells is RER found?

Answer 11

Plant and Animal Cells

Question 12

What is the surface of RER covered in?

Answer 12

Ribosomes

Question 13

What is RER formed of?

Answer 13

Continuous folas of membrane with the nuclear envelope.

Question 14

What does the RER process?

Answer 14

Proteins made by the ribosomes.

Question 15

Where is the ER found?

Answer 15

Plant and Animal Cells.

Question 16

What on the surface does RER have that ER doesn’t have?

Answer 16

Ribosomes, function is distinct to the RER.

Question 17

What processes is the RER involved in and for what molecules?

Answer 17

Production, Processing and storage of lipids, carbohydrates and steroids.

Question 18

Where is the Golgi Apparatus found?

Answer 18

Plant and Animal Cells

Question 19

What is the Golgi Apparatus like?

Answer 19

Flattened sacs of membrane, similar to the ER.

Question 20

What is the role of the Golgi Apparatus?

Answer 20

Modifies proteins and lipids before packaging them into Golgi vesicles.

Question 21

What does the Golgi Vesicles do?

Answer 21

Transport proteins and lipids to destination.

Question 22

What happens to the proteins that go through the Golgi apparatus?

Answer 22

Usually exported, then put into lysosomes or delivered to membrane bound organelles.

Question 23

Where are ribosomes found?

Answer 23

In all cells.

Question 24

Which part of the cell are ribosomes found?

Answer 24

Found freely in the cytoplasm of all cells or as part of the RER.

Question 25

What is each ribosome a complex of?

Answer 25

Ribosomal RNA (rRNA) and proteins.

Question 26

What ribosomes are in Eukaryote's?

Answer 26

80S ribosomes (60S and 40S subunits)

Question 27

What ribosomes are in Prokaryote's , Mitochondria and Chloroplasts?

Answer 27

70S ribosomes (50S and 30S subunits)

Question 28

What are ribosomes the site of?

Answer 28

Translation (Protein Synthesis)

Question 29

What are Lysosomes?

Answer 29

Specialist forms of vesicles which contain hydrolytic enzymes (break down biological molecules)

Question 30

What do lysosomes break down?

Answer 30

Waste materials e.g. worn out organelles.

Question 31

Which specific cells are Lysosomes used in?

Answer 31

Used extensively by cells of the immune system and in apoptosis.

Question 32

In what type of cells are chloroplasts found?

Answer 32

In plant cells.

Question 33

Are chloroplasts larger or smaller than Mitochondria?

Answer 33

Larger.

Question 34

What are chloroplasts surrounded by?

Answer 34

A double membrane.

Question 35

What is the membrane bound organelle which contains chlorophyll?

Answer 35

Thylakoids

Question 36

What do the Thylakoids do?

Answer 36

Stack to form structures called grana.

Question 37

What joins the grana together?

Answer 37

Lamellae.

Question 38

Chloroplasts are the site of what

Answer 38

site of photosynthesis.

Question 39

Where does the light-independent stage happen?

Answer 39

Stroma.

Question 40

Where does the light-dependent stage happen?

Answer 40

Thylakoids.

Question 41

What are all cells surrounded by?

Answer 41

A Plasma Membrane

Question 42

What is the role of the Plasma Membrane?

Answer 42

Controls the exchange of materials between the internal cell environment and the external environment.

Question 43

The Plasma Membrane is...

Answer 43

Partially Permeable.

Question 44

The plasma cell membrane is formed from what?

Answer 44

A phospholipid bilayer of phospholipids around 10nm wide.

Question 45

The structure looks static, but what is actually constantly moving?

Answer 45

The phospholipids and proteins forming the bilayer.

Question 46

What are Centrioles?

Answer 46

Hollow fibres made of microtubules.

Question 47

How is a Centrosomes formed?

Answer 47

Two centrioles at rights angles to each other.

Question 48

What does a Centrosome do?

Answer 48

Organises the spindle fibres during cell division.

Question 49

Where are the Centrioles not found?

Answer 49

In flowering plants and fungi.

Question 50

What are cilia?

Answer 50

Hair like projections.

Question 51

What are cilia made out of?

Answer 51

Microtubules.

Question 52

What is the role of cilia?

Answer 52

Allows the movement of substances over cell surface.

Question 53

Where is the flagella found?

Answer 53

Specialised Cells.

Question 54

What is the structure of the flagella?

Answer 54

Made of long microtubes, similar to the cilia.

Question 55

In what cells is the cell wall found?

Answer 55

In plant cells only.

Question 56

Where is the cell wall and what is it's role?

Answer 56

Formed outside of the cell membrane and offers structural support to cell.

Question 57

How is this structural support given?

Answer 57

Given by the polysaccharide cellulose in plants and pepticloglycan in most bacterial cells.

Question 58

What connects the cytoplasm of neighbouring plant cells to the cell wall?

Answer 58

Narrow threads (surrounded by cell membrane) called plasmodesmata.

Question 59

What is the permeability of the cell wall to most substances?

Answer 59

Freely permeable.

Question 60

The cell wall is freely permeable, unlike what other sub-cellular structure?

Answer 60

The Plasma Cell Membrane.