Chapter 3: Cell structure

Question 1

cell surface membrane

Answer 1

• regulates the movement of substances in and out of the cell
• mainly made of lipids and proteins
• fluid-mosaic model
• has receptor molecules which are needed for cell recognition and responding to chemicals such as hormones

Question 2

nucleus

Answer 2

• controls the cell’s activity by controlling the transcription of certain genes
• nuclear envelope
• nuclear pores
• contains chromosomes/DNA
• nucleolus

Question 3

Mitochondria

Answer 3

• site of aerobic respiration
• site of ATP production
• double membrane
• cristae: folds of inner membrane
• matrix: enzymes involved in respiration

Question 4

Golgi apparatus

Answer 4

• processes and packages proteins and lipids
• makes lysosomes
• fluid filled sacs
• vesicles

Question 5

Lysosomes

Answer 5

• fluid filled sacs
• digestive enzymes called lysozymes
• break down worn out parts of cell and digest invading cells

Question 6

Golgi vesicles

Answer 6

• stores lipids and proteins
• transports out of cell
• fluid filled sacs
• produced by Golgi

Question 7

Ribosome

Answer 7

• site of protein synthesis
• floats free or attached to RER
• made up of proteins and RNA

Question 8

Rough endoplasmic reticulum

Answer 8

• folds and processes proteins
• ribosomes

Question 9

Smooth endoplasmic reticulum

Answer 9

• no ribosomes
• synthesises and processes lipids

Question 10

Cell wall

Answer 10

• plant, algae** and **fungi
• structural support
• rigidity
• cellulose
• chitin

Question 11

Chloroplast

Answer 11

• site of photosynthesis
• plants and algae
• thylakoids: fluid filled scas
• grana: stacks of thylakoids
• stroma: gel-like; enzymes sugars organic acids
• double membrane

Question 12

Cell vacuole

Answer 12

• helps maintain pressure inside cell
• filled with cell sap: solution of salts and sugar
• turgidity - prevents wilting
• membrane called tonoplast

Question 13

What is a plant cell wall made of?

Answer 13

cellulose

Question 14

What is a fungal cell wall made of?

Answer 14

chitin

Question 15

What is a tissue?

Answer 15

a group of cells that work together do a similar job

Question 16

What is the function of ribosomes?

Answer 16

Ribosomes are a cell structure that makes protein. Protein is needed for many cell functions such as repairing damage or directing chemical processes. Ribosomes can be found floating within the cytoplasm or attached to the endoplasmic reticulum.

Question 17

What is the function of mitochondria?

Answer 17

The main job of mitochondria is to perform cellular respiration. This means it takes in nutrients from the cell, breaks it down, and turns it into energy. This energy is then in turn used by the cell to carry out various functions. The mitochondria are in charge of producing the energy currency of the cell, ATP during respiration.

Question 18

What is the function of chloroplasts?

Answer 18

Chloroplasts job is to convert light energy from the sun into sugars that can be used by cells. The entire process is called photosynthesis and it all depends on the little green chlorophyll molecules in each chloroplast.

Question 19

What is the function of the SER and the RER?

Answer 19

The rough endoplasmic reticulum is an organelle that produces proteins and helps them fold properly. The smooth endoplasmic reticulum is another organelle that synthesizes lipids. It produces phospholipids and cholesterol that help stabilize the membranes of the entire cell.

Question 20

Viruses are acellular. What does this mean?

Answer 20

It means that they are not really cells so they aren’t alive. They are actually nucelic acids surounded by protein

Question 21

What is the structure of a virus?

Answer 21

• no plasma membrane - no ctypolasm - no ribosomes - protein coat called capsid - genetic material - attachment proteins

Question 22

What is the structure of a virus?

Answer 22

• no plasma membrane, ctypolasm, ribosomes or nucleus - protein coat called capsid - genetic material - DNA or RNA - attachment proteins

Question 23

How do viruses replicate?

Answer 23

They use host cells to replicate themselves - attachment proteins bind to complimentary receptor proteins on surface of host cell - different viruses have different attachment proteins - viruses can be specific to one type of cell and some viruses can infect lots of cells - viral genetic material injected into host cell - host cell uses its own machinery (enzymes and ribosomes) to manufacture the components to make new viruses

Question 24

How do viruses replicate?

Answer 24

They use host cells to replicate themselves - attachment proteins bind to complimentary receptor proteins on surface of host cell - different viruses have different attachment proteins - viruses can be specific to one type of cell and some viruses can infect lots of cells - viral genetic material injected into host cell - host cell uses its own machinery (enzymes and ribosomes) to manufacture the components to make new viruses

Question 25

What are microtubules?

Answer 25

Microtubules are long, hollow, cylindrical structures made of a protein called tubulin. They run in all directions through the cytoplasm making up the cytoskeleton.