2.1 Eukaryotic cells

Question 1

Where are eukaryotic cells found?

Answer 1

In animal and plant cells

Question 2

Where are prokaryotic cells found?

Answer 2

In single celled organisms, such as bacteria

Question 3

What is the function of the nucleus?

Answer 3

It contains the DNA and instructs the rest of the cell (organelles)

Question 4

What is ultra structure?

Answer 4

It is the internal structure of a cell, can be seen under an electron microscope

Question 5

What do all organelles in a eukaryotic cell have and why?

Answer 5

A membrane which protects the organelle and controls the conditions within it (input and output)

Question 6

What does the nucleus contain?

Answer 6

• nuclear envelope
• nuclear pores
• chromatin
• nucleolus

Question 7

What is the nuclear envelope?

Answer 7

A double membrane controlling material entry and exit

Question 8

What are nuclear pores?

Answer 8

Gaps in the membrane allowing large molecules such as mRNA out of the nucleus

Question 9

What is chromatin?

Answer 9

Made out of proteins and DNA, it controls cell activity

Question 10

What does the nucleolus do?

Answer 10

It is responsible for making ribosomes

Question 11

What are the functions of the nucleus?

Answer 11

• produce mRNA for protein synthesis
• retain genetic material in the form of DNA or chromosomes
• manufacture ribosomal RNA and ribosomes

Question 12

What does the mitochondria contain? And what is the mitochondria?

Answer 12

• a double membrane
• Cristoe
• matrix
- the site of aerobic respiration, energy is derived from fuels here and converted into ATP

Question 13

What does the double membrane do?

Answer 13

The outer membrane controls the flow if materials in/out

Question 14

What is Cristoe and what does it do?

Answer 14

• it is the extension of the inner membrane it increases surface area for the attachment of enzymes

Question 15

What is the matrix and what does it do?

Answer 15

It is a semi rigid structure containing proteins, lipids, trace DNA, and the enzymes involved in respiration
it is also the site of the krebs cycle

Question 16

What is the endoplasmic reticulum?

Answer 16

A system of sheet like membranes throughout the cytoplasm

Question 17

What are the two types of endoplasmic reticulum?

Answer 17

there is the ROUGH ENDOPLASMIC RETICULUM and the SMOOTH ENDOPLASMIC RETICULUM

Question 18

What does the rough endoplasmic reticulum look like, and why?

Answer 18

It is bumpy because it has ribosomes embedded on its surface to give it a large surface area for protein synthesis

Question 19

What is the function of the rough endoplasmic reticulum?

Answer 19

It acts as a pathway to transport proteins out of the cell

Question 20

What does the smooth endoplasmic reticulum look like and why?

Answer 20

It is smooth as it has no ribosomes embedded on the surface

Question 21

What is the function of the smooth endoplasmic reticulum?

Answer 21

Used for protein synthesis, it stores and transports lipids and carbohydrates

Question 22

Where is the reticulum found?

Answer 22

In close proximity of not attached to the nucleus

Question 23

What does the Golgi apparatus do?

Answer 23

It modifies, packages and transports lipids and proteins

Question 24

What is the structure of the Golgi apparatus?

Answer 24

• similar to the smooth ER
• more compact
• flattened stacks of membranes with rounded structures called vessicles

Question 25

What are the functions of the Golgi apparatus?

Answer 25

* adds carbohydrates to proteins to make glycoproteins * produces secretary enzymes * secretes carbohydrates * transports and modifies lipids * forms lysosomes

Question 26

What are lysosomes?

Answer 26

- formed from the Golgi apparatus they contain digestive enzymes - round organelle surrounded by a membrane with no clear internal structure

Question 27

What do lysosomes do?

Answer 27

- isolate potentially harmful enzymes from the rest of the cell - break down material ingested by phagocytic cells such as white blood cells - release enzymes to the outside of the cell - digest worn out organelles - break down cells when they have died

Question 28

Where a ribosomes found?

Answer 28

In the cytoplasm floating freely or attached to the rough ER

Question 29

What are ribosomes used for?

Answer 29

Protein synthesis

Question 30

What are the two types of ribosomes?

Answer 30

* 80s | * 70s

Question 31

Where are 80s found?

Answer 31

In eukaryotic cells, they are about 25nm

Question 32

Where are 70s found?

Answer 32

Found in prokaryotic cells, they are smaller

Question 33

What are microvilli?

Answer 33

Finger like projections of epithelial cells to increase surface area for absorption

Question 34

What make up the cytoskeleton?

Answer 34

Micro tubules | Micro filaments

Question 35

What are microfilments are what are they involved in?

Answer 35

* protein action | * Involved in cell movement and cell division

Question 36

What are micro tubules and what are they involved in?

Answer 36

* globular proteins that form tubes * determine cell shape * direct movement of organelles within the cell

Question 37

What does the nucleus make?

Answer 37

MRNA for protein synthesis | Manufactures ribosomal RNA and ribosomes

Question 38

What are ribosomes made up of?

Answer 38

Proteins and RNA

Question 39

What is the plasma cell surface membrane?

Answer 39

A lipid bilayer in which proteins are embedded

Question 40

Where is the cell surface membrane found?

Answer 40

On the surface of animal cells | Just inside the cell wall of plant cells and prokaryotic cells

Question 41

What does the cell membrane do?

Answer 41

Regulates movement of substances in and out of the cell

Question 42

What molecules does the cell surface membrane have?

Answer 42

Receptor molecules allowing it to respond to chemicals like hormones

Question 43

What is the cell wall?

Answer 43

A rigid structure found in plant cells that consists mainly of the carbohydrate cellulose

Question 44

What is the function of the cell wall?

Answer 44

To support the plant cells (leaves, roots and stems)

Question 45

What are vesicles?

Answer 45

Small fluid filled sacs in he cytoplasm that are surrounded by a membrane

Question 46

What do vesicles do?

Answer 46

They transport substances in and out of the cell (via the cell membrane) and between organelles

Question 47

Where are vesicles formed?

Answer 47

Some are formed at the Golgi apparatus or the ER | Others form at the cell surface

Question 48

What is centriole?

Answer 48

Small hollow cylinders made of microtubules

Question 49

Where are centrioles found?

Answer 49

In animal cells | Only in some plant cells

Question 50

What are centrioles involved in?

Answer 50

The separation of chromosomes in cell division

Question 51

What is cilia?

Answer 51

Small hair like structures found on the surface membrane of some animal cells

Question 52

What does cilia look like in cross section?

Answer 52

* Has an outer membrane | * Nine pairs of protein molecules on the outside and two micro tubules in the middle

Question 53

What do the micro tubules in the cilia allow?

Answer 53

The cilia to move

Question 54

What is the movement in cilia used for?

Answer 54

It is used by the cell to move substances along the cell surface

Question 55

What are flagella?

Answer 55

* like cilia but longer | * they stick our from the cell surface

Question 56

What does flagellum look like?

Answer 56

* surrounded by a plasma membrane | * inside they have a pair of micro tubules in the centre and 9 pairs around the edge

Question 57

What makes flagellum move?

Answer 57

The micro tubules contract to make flagellum move

Question 58

What is flagella used for?

Answer 58

It is used to make cells move, it acts like an outward motor E.g. When a sperm cell swims

Question 59

What are chloroplasts?

Answer 59

Small flattened structures found in plant cells.

Question 60

What does a chloroplast do?

Answer 60

* It is the site of photosynthesis | * Some parts of photosynthesis happen in the grana and others in the strong

Question 61

What is the structure of chloroplasts?

Answer 61

* surrounded by a double membrane * has membranes inside called thylakoid membranes * these membranes are stacked to form grana * grana are linked by lamella (thin prices of thylakoid membrane)

Question 62

How big are eukaryotic cells?

Answer 62

10-100 micrometers