Cell Structure

Question 1

What is the structure of a eukaryotic cell?

Answer 1

A eukaryotic cell has a nucleus, membrane-bound organelles, and a cytoskeleton.

Question 2

What is the function of nuclear pores?

Answer 2

Nuclear pores allow the transport the mRNA to leave and enter the nuclues and hormones aswell.

Question 3

What is the nuclear envelope?

Answer 3

The nuclear envelope is a double membrane that seperates the cells contents from the nucleus.

Question 4

What is chromatin?

Answer 4

Chromatin is genetic material (DNA and histone proteins) that condenses to form chromosomes during cell division.

Question 5

What is the nucleolus?

Answer 5

The nucleolus is a structure within the nucleus where RNA is produced.

Question 6

What is the rough endoplasmic reticulum (RER)?

Answer 6

The rough endoplasmic reticulum is a network of flattened membrane bound sacs called cisternae. They are continuous with the nuclear pores. They also have ribosomes on their surface. Protein sinthesis occurs here.

Question 7

What is the relationship between the nuclear envelope and the endoplasmic reticulum?

Answer 7

The nuclear envelope is continuous with the endoplasmic reticulum membrane.

Question 8

What is the Cisternae

Answer 8

Contiuous with neclear membrane and forms channels to transport sustances (proteins to golgi)

Question 9

What is the role of enzymes in the cell?

Answer 9

Enzymes are involved in metabolic processes and help in the synthesis of proteins.

Question 10

What is the structure of mitochondria?

Answer 10

(double membrane) Mitochondria have an outer membrane and an inner membra. The inner membrane is folded into cristae. They also have a fluid filled matrix.

Question 11

What shape can mitochondria have?

Answer 11

Mitochondria can be shaped like spherical , rod shaped or branched forms.
THEY HAVE THEIR OWN DNA

Question 12

What is the role of mitochondria?

Answer 12

It is to generates ATP which is used for aerobic respiration.

Question 13

What are secretory vesicles?

Answer 13

Secretory vesicles contain modified proteins that will be secreted coming for the Golgi apparatus

Question 14

What do vesicles contain?

Answer 14

Vesicles contain various substances, including proteins.

Question 15

What is the role of the Golgi apparatus?

Answer 15

The Golgi apparatus is involved in modifying, sorting, and packaging proteins. By adding sugar to make glycoproteins and adding lipids to make lipoproteines

Question 16

Structure of Golgi?

Answer 16

A stack of membrane bound flattened sacs.

Question 17

What do lysosomes do? And what is their structure like?

Answer 17

Contain powerful digestive enzymes which are used to break down materials by hydrolysis. Their structure is like a spherical sac surrounded by a membrane.

Question 18

What does the smooth endoplasmic recticulum do? And its structure?

Answer 18

Cisternae (continuous with nuclear membrane) to transport lipids, it has no ribosomes here and has enzymes involved in lipid metabolism and synthesis and carbohydrate metabolism

Question 19

What is the function of the ribosome.

Answer 19

Function: It is the site of protein synthesis. (Where the mRNA assemebles proteins from amino acids)

Question 20

What is the structure of a chloroplast?

Answer 20

They have an outer and a inner membrane. They have fluid filled matarix called stroma (where second stage of photosynthesis happens) They also have a network of flattend disk called thylakiod (these are continous with the inner membrane). Each disk is called a granum ( first stage of photosynthesis).

Question 21

What is the function of chloroplast?

Answer 21

It is the site of photosynthesis which is driven by light energy.

Question 22

What does the Plasma/ Cell surface membrane do?

Answer 22

It controles what enters and exits the cell. Made out of phospholipid bilayer.

Question 23

What are centriols?

Answer 23

They are two bundles of microtubules at right angles made of tubulin protein. They take part in mitosis to form spindle fibres.

Question 24

Cell wall (plant cell) what does it do?

Answer 24

It provides high tensile strength, it is insoluble and inert. It is made of cellulose.
- Maintains high cell shape
- provides to strength and support of the whole plant.
- Also are permable.

Question 25

What is the permanent vacuole (plant cell)?

Answer 25

The mebrane surrounding the vacuole is called a tonoplast. It is involved in removing unwanted substances from the cell and altering the cell shape by changing the amount of water in the vacuole (becoming turgid or flaccid)

Question 26

What happens in the secreation of proteins?

Answer 26

The mRNA leaves the nucleus through the nuclear pores, then it attaches to a ribosome (RER/ Free), then protein synthesis occurs to make the protein, Then it will go in a vesicel and go to the golgi apparatus to get modified and packaged into a vesicle again and then the vesicle will be moved to the cell surface membrane were exocytosis occurs.

Question 27

What is the role of cytoskeleton?

Answer 27

The cytoskeleton is improtant in whole cell support; movement of cillia and flagella; Changing cell shape;moving organelles (like a vesicle; movement of chromosomes.

ALL COMPONENTS WITHIN THE CYTOSKELETON NEED ATP TO WORK.

Question 28

What is microfilaments?

Answer 28

They are made of actin, they contract and are used in cytokinesis and changes cell shape.

Question 29

What is a microtubules?

Answer 29

Made of golbular tubulin protein, Moves chromosomes in mitosis by forming spindle fibres. Moves organelles around.

Question 30

What is intermidiate filaments?

Answer 30

made of actin and microtubles and they give mechanical strength and whole cell support.

Question 31

What are cell walls in bacterial cells made out of?

Answer 31

They are made of murein or peptidoglycan; provide with high tensile strength.

Question 32

what is the differences between eukaryotic cells and prokaryotic?

Answer 32

1- Prokaryotic cell ribosome =70s and eukaryotic = 80s.
2- Prokaryotic = no membrane bound organells, eukaryotic = yes.
3- prokaryotic = circular DNA and eukaryotic = DNA with histone proteins formed into chromosomes.
4- prokaryotic cell divide by binary fission, eukaryotic cells divide by mitosis.