Cell structure - eukaryotic cells

Question 1

What are eukaryotic cells?

Answer 1

cells that contain a nucleus and other membrane bound organelles.

Question 2

where are membrane bound organelles found?

Answer 2

Animals, plants, fungi

Question 3

what are the membrane bound organelles found in plant and animal cells?

Answer 3

cell surface membrane
nucleus
mitochondria
endoplasmic reticulum
golgi apparatus and golgi vesicles
lysosomes
ribosomes
cell wall

Question 4

what other membrane bound organelles are found in the plant cells only?

Answer 4

chloroplasts
cell wall
cell vacuole

Question 5

what other membrane bound organelles are found in the algae only?

Answer 5

cell wall
chloroplasts

Question 6

what other membrane bound organelles are found in fungi only?

Answer 6

cell wall

Question 7

What is the nucleus and its function?

Answer 7

the nucleus is the largest organelle in a cell which contains the genetic material (protein bound linear DNA) .

control centre of the cell through the production of mRNA and tRNA.

retains genetic material of the cell in the form of DNA and chromosomes

manufactures rRNA and ribosomes.

Question 8

what is the nuclear envelope and its function?

Answer 8

A double membrane that surrounds the nucleus.
Its outer membrane is continuous with the endoplasmic reticulum of the cell.

FUNCTION: it controls the entry and exit of materials in and out of the nucleus and contains the reactions taking place within it.

Question 9

what are nuclear pores and its function?

Answer 9

Allows the passage of large molecules such as messenger RNA out of the nucleus

Question 10

what is the nucleoplasm?

Answer 10

granular jelly like material

Question 11

what is the nucleolus?

Answer 11

A dense region where ribosomes are manufactured.

Question 12

what is the mitochondrion and its function?

Answer 12

-organelle with a double membrane
-inner membrane is folded into structures known as cristae
inner area is known as the matrix

FUNCTION: it is the site of aerobic respiration and responsible for the production of ATP

Question 13

what does the matrix contain?

Answer 13

-protein lipids ribosomes and DNA which allows the mitochondria to control the production of some of their own proteins.
-many enzymes involved in respiration are found in the matrix.

Question 14

what is the chloroplast and its function?

Answer 14

Flattened structures found in the plant and algal cells which are surrounded by a double membrane.

FUNCTION: harvest sunlight for photosynthesis

Question 15

what is the grana?

Answer 15

They are stacks of thylakoids

Question 16

what are within the thylakoids?

Answer 16

chlorophyll

Question 17

function of thylakoids?

Answer 17

where light dependant reactions take place

Question 18

what are the stacks of thylakoids linked with?

Answer 18

lamellae

Question 19

what happens in the stroma?

Answer 19

it is a fluid filled matrix where the second stage of photosyntheses (synthesis of sugars) take place?

Question 20

what are the adaptations of grana?

Answer 20

it provides a large surface area, allowing light to be absorbed more efficiently.

Question 21

what is the endoplasmic reticulum and its function?

Answer 21

-it can be rough (with ribosomes) and smooth (without ribosomes).
-it is continuous with the outer nuclear membrane.

Question 22

what is the function of the RER?

Answer 22

Folds and processes proteins that have been made at the ribosomes.
- has ribosomes present on the outer structures.
- provides large surface area for the synthesis of proteins and glycoproteins
-provides a pathway for the transport of materials (proteins) throughout the cell.

Question 23

what is the function of the SER?

Answer 23

Synthesises, stores and transports carbohydrates.

Question 24

what is the Golgi Apparatus and its function?

Answer 24

A series of flattened sacs surrounded by the membrane.
It is where new proteins and lipids are processed and packaged.
Forms lysosomes.

Question 25

what is the golgi vesicle and its function?

Answer 25

They are pinched from the sacs form the golgi apparatus.

FUNCTION: it stores the lipids and proteins made by the Golgi Apparatus and transports them out of the cell surface membrane.

Question 26

what is the function of lysosomes?

Answer 26

they contain digestive enzymes called lysozymes used to digest invading pathogens.
Hydrolyses (breaks down) phagocytic cells.
Digests worn out organelles for reuse of materials.
EXOCYTOSIS - releases enzymes to the outside of cells in order to destroy material around the cell.
AUTOLYSIS- completely break down cells after they have died.

Question 27

what are ribosomes and its function?

Answer 27

Small cytoplasmic granules found in cells.
Made up of 2 sub-units of protein and RNA. They are the site of protein synthesis.

Question 28

what are the 2 types of ribosomes and where are they found?

Answer 28

80S - found in the eukaryotic cells - 25nm in diameter
70S - found in prokaryotic cells, mitochondria and chloroplasts.

Question 29

what is the cell wall and its function?

Answer 29

A rigid structure that surrounds a plant algal and fungal cell.

FUNCTION: supports the cell and prevents it from changing shape. Strong enough to resist hydrostatic pressure. Allows water to pass along.

Question 30

What are cell walls made of in a plant cell?

Answer 30

polysaccharides such as cellulose.

Question 31

what are microfibrils?

Answer 31

Larger structures of cellulose molecules when they form hydrogen bonds with each-other.
They have a mesh-like structure which is strong and contributes to the mechanical strength of a plant cell wall

Question 32

what is the cell wall made up of in a algae cell?

Answer 32

cellulose and glycoproteins

Question 33

what is the cell wall made up of in fungal cell?

Answer 33

polysaccharides called chitin, glycan and glycoproteins.

Question 34

what is a vacuole and its functions?

Answer 34

A fluid filled sac bounded by a single membrane (tonoplast).
contains solution of mineral salts , sugars, amino acids, pigments.

FUNCTION: makes cells turgid and provides support - helps plants from wilting.
temporary store of sugars and amino acids
helps get rid of waste chemicals

Question 35

what is the cell surface (plasma) membrane and its function?

Answer 35

• found on the surface of animal cells
• found on the inside of the cell wall of plant cells

FUNCTION: regulates the movement of substances into and out of the cell.
- Has receptor molecules which allows it to respond to chemicals such as hormones.