Cell Biology

Question 1

What is a eukaryote?

Answer 1

A eukaryote is a cell that contains its genetic information enclosed in a nucleus. Typically animal and plant cells.

Question 2

What is a prokaryote?

Answer 2

A prokaryote is a microscopic organism which contains no distinct nucleus, and has free DNA, and no membrane bound organelles.

Question 3

What is in eukaryotes that isn’t in prokaryotes?

Answer 3

Nucleus, membrane bound organelles

Question 4

What is a lysosome?

Answer 4

A specialised vesicle.

Question 5

What is the structure and function of a lysosome?

Answer 5

Structure- no sub organelle, fluid-filled sac

Function- contains hydrologic enzymes, digests invading pathogens ALSO digests worn out components of cell (“suicide-sack”)

Question 6

Describe the structure and function of the nuclear envelope

Answer 6

Structure- double membrane and contains pores

Function- pores control what enters and leaves nucleus

Question 7

Describe the structure and function of the nucleolus

Answer 7

Structure- contains RNA, ribosomal DNA and ribosomal proteins

Function- produces ribosomes, contains

Question 8

Describe the structure and function of the nucleus

Answer 8

Structure- made of chromatin (a complex structure composed of DNA and proteins called histones) , chromatin coils to form chromosomes

Function- controls cells activities

Question 9

Describe the structure and function of ribosomes

Answer 9

Structure- float free in the cytoplasm OR rough ER, made of two subunits and proteins and RNA

Function- site of protein synthesis

Question 10

What is mitochondria?

Answer 10

It is a membrane bound organelle in the cytoplasm of eukaryotes, and is the site of respiration.

Question 11

Describe the structure and function of the rough ER

Answer 11

Structure – fluid filled sac surrounded by a membrane studied with ribosomes
Function – processes and fold proteins

Question 12

Describe the structure and function of the Smooth Endoplasmic Reticulum (smooth ER)

Answer 12

Structure- membranes enclosing fluid filled sacs

Function- synthesis and processes lipids and carbohydrates

Question 13

Describe and explain the structure/functional of the Golgi Apparatus

Answer 13

Structure – membrane enclosed flattened sacs
- vesicles at edge for transportation

Function - processes and packages proteins and lipids and sends them off to vesicles to be secreted, makes lysosomes

Question 14

Describe the structure and function of the vesicle

Answer 14

S- fluid filled sac

F- transports substances in and out of cells via plasma membrane

Question 15

What are the 4 parts of mitochondria?

Answer 15

Outer / inner membrane
Cristal
Matrix

Question 16

Describe the structure and function of the mitochondria

Answer 16

S- double membrane

• highly folded by cristae TO INCREASE S.A
• matrix contains enzymes for respiration

F- site of respiration
- contains maternal DNA

Question 17

What are the parts of chloroplasts?

Answer 17

• double membrane
• granum / grana
• stroma
• lamellae

Question 18

Describe the structure and function of the chloroplast

Answer 18

S — double membrane
- thylakoids membranes stacked up called grana
-grana connected by pieces of thylakoid membrane called lamellae
F — site of photosynthesis = some in grana, some in thick liquid called stroma

Question 19

What do chloroplasts, like mitochondria, contain?

Answer 19

DNA, and contain ribosomes in stroma

Question 20

Describe the structure and function of the cell wall.

Answer 20

Structure - cellulose in plants, peptidoglycan in prokarytotes, chitin in fungi
Function- keeps cell TURGUD, keeps cell UPRIGHT, prevents cell BURSTING.

Question 21

Describe the structure and function plasma membrane.

Answer 21

Structure - Phospholipid bilayer, with integral proteins

Function - regulates movement of substances in and out of cell

Question 22

What is it called when organelles in a cell work together to carry out a specific function? Give example.

Answer 22

Division of Labour

protein synthesis

Question 23

Describe the structure and function of the centriole

Answer 23

Structure- small hollow cylinders made opus of microtubules

Function- involved in separation of chromosomes in cell division

Question 24

Describe the process of protein synthesis inside a cell, how do the organelles work together?

Answer 24

,

Question 25

How do vesicles transport substance out of the cell membrane ?

Answer 25

They fuse with the plasma membrane

Question 26

What is the cytoskeleton?

Answer 26

A network of protein fibres, actin filaments and microtubules within the cytoplasm.

Question 28

What are the three types of protein fibres in the cytoskeleton?

Answer 28

Microfilaments Microtubules Intermediate Fibres

Question 29

Describe the structure and function of microfilaments?

Answer 29

Structure— contractile fibres made up of protein called actin Function— responsible for cell movement and cell contraction during cytokinesis

Question 30

Describe the structure and function of microtubules

Answer 30

Structure— globular tubulin proteins | Function— act as track for vesicles, also polymerise to forms spindle fibres

Question 31

Describe the structure and function of intermediate fibres

Answer 31

Structure— various proteins | Function— mechanical strength to cell, and maintains cells integrity (togetherness of organelles/ otherwise fall apart)

Question 32

Name four things secreted by the cell into the blood

Answer 32

-insulin -collagen -mucus -enzymes etc.

Question 33

How do the structures of microfilaments and microtubules allow them to be involved in the movement of cells but intermediate fibres are not?

Answer 33

Microfilaments are composed of acting which is contractile. Microtubules have tubal in which polymerises and this leads to a change in length of the filament and results in movement of cells. Intermediate fibres have fixed lengths for stability.

Question 34

Name different types of staining

Answer 34

Differential staining | immuno staining

Question 35

Describe the purpose of differential staining

Answer 35

A dye or stain is used to differentiate one component or cellular structure from another

Question 36

Why is staining used in microscopy?

Answer 36

Staining provides contrast as different organelles absorb stain differently.

Question 37

Suggest why all measurements should be converted into the same units before calculation

Answer 37

– Simplifies the calculation | – reduces errors

Question 38

What is the function of the cytoskeleton?

Answer 38

— necessary for the shape and stability of the cell — controls cell movement and movement of the cells organelles (track) — provides mechanical support