2.1.1 Cell Structure

Question 1

what is the structure of nucleus?

Answer 1

1. nuclear envelope
   —> double membrane
2. nuclear pores
3. nucleoplasm
   —> jelly-like material
4. chromosomes
   —> protein-bound and linear dna
5. nucleolus
   —> smaller sphere inside nucleus
   —> site of rna production and makes ribosomes

Question 2

what is the function of the nucleus ?

Answer 2

1. nuclear envelope - separates content of nucleus from rest of the cell
2. pores - enable larger substances to leave the nucleus
3. nucleolus - ribosomes are made
4. chromosomes - contain organisms’s genes

Question 3

what is the structure of rough endoplasmic reticulum? (RER)

Answer 3

• system of membranes with cisternae
• coated with ribosomes

Question 4

what is the function of the RER?

Answer 4

• intraceulluar transport system
• cisternae form channels for transporting substances from one area of a cell to another

Question 5

what is the structure of smooth endoplasmic reticulum? (SER)

Answer 5

• system of membranes containing cisternae
• no ribosomes

Question 6

what is the function of SER?

Answer 6

• contain enzymes that catalyse reactions involved with lipid metabolism
• involved with synthesis and transport of lipids

Question 7

what is the function of the golgi apparatus?

Answer 7

• proteins are modified by adding carbohydrates to proteins to form glycoproteins
• proteins are packaged into vesicles

Question 8

what is the function of ribosomes?

Answer 8

• site of protein synthesis
• mRNA assembles proteins from amino acids

Question 9

what’s the function of mitochondria?

Answer 9

ATP is made during aerobic respiration

Question 10

what is the function of a lysosome?

Answer 10

• contain powerful digestive enzymes
• used to break down materials that are not needed anymore
• broken down through the process of hydrolysis

Question 11

what’s the function of cell surface membrane?

Answer 11

• controls what goes in and out of the cell
• made out of phospholipid bilayer

Question 12

what’s the function of centrioles?

Answer 12

• take part in mitosis to form spindle fibres
• only found in animals

Question 13

what is the function of a cell wall?

Answer 13

• provides high tensile strength
• insoluble
• inert

Question 14

what is the cell wall in bacteria made up of?

Answer 14

peptidoglycan

Question 15

what is the function of vacuole?

Answer 15

• membrane surrounding it is called tonoplast
• becomes turgid or flaccid altering the cell shape

Question 16

what’s a vesicle?

Answer 16

membrane bound organell which is used to transport substances

Question 17

Why do we need to stain specimens?

Answer 17

Allows specimen to become visible and to improve contrast

Question 18

what are examples of stains?

Answer 18

1. Methylene blue —> stains dna
2. Eosin —> stains cell cytoplasm

Question 19

Why are transmission microscopes used? (TEM)

Answer 19

To look at organelle detail

Question 20

Why are scanning electron microscopes used? (SEM)

Answer 20

To look at the cell surface

Question 21

What is the magnification?

Answer 21

number of times larger the image is in comparison to the object

Question 22

What is resolution?

Answer 22

Ability to distinguish between small structures that are close together

Question 23

Why does the specimen have to be thin in a light microscope?

Answer 23

So maximum light can penetrate sample