2.1 Eukaryotic cells Flashcards Preview

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Flashcards in 2.1 Eukaryotic cells Deck (62):
1

Where are eukaryotic cells found?

In animal and plant cells

2

Where are prokaryotic cells found?

In single celled organisms, such as bacteria

3

What is the function of the nucleus?

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

4

What is ultra structure?

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

5

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

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

6

What does the nucleus contain?

• nuclear envelope
• nuclear pores
• chromatin
• nucleolus

7

What is the nuclear envelope?

A double membrane controlling material entry and exit

8

What are nuclear pores?

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

9

What is chromatin?

Made out of proteins and DNA, it controls cell activity

10

What does the nucleolus do?

It is responsible for making ribosomes

11

What are the functions of the nucleus?

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

12

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

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

13

What does the double membrane do?

The outer membrane controls the flow if materials in/out

14

What is Cristoe and what does it do?

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

15

What is the matrix and what does it do?

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

16

What is the endoplasmic reticulum?

A system of sheet like membranes throughout the cytoplasm

17

What are the two types of endoplasmic reticulum?

there is the ROUGH ENDOPLASMIC RETICULUM and the SMOOTH ENDOPLASMIC RETICULUM

18

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

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

19

What is the function of the rough endoplasmic reticulum?

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

20

What does the smooth endoplasmic reticulum look like and why?

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

21

What is the function of the smooth endoplasmic reticulum?

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

22

Where is the reticulum found?

In close proximity of not attached to the nucleus

23

What does the Golgi apparatus do?

It modifies, packages and transports lipids and proteins

24

What is the structure of the Golgi apparatus?

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

25

What are the functions of the Golgi apparatus?

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

26

What are lysosomes?

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

27

What do lysosomes do?

- 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

28

Where a ribosomes found?

In the cytoplasm floating freely or attached to the rough ER

29

What are ribosomes used for?

Protein synthesis

30

What are the two types of ribosomes?

• 80s
• 70s

31

Where are 80s found?

In eukaryotic cells, they are about 25nm

32

Where are 70s found?

Found in prokaryotic cells, they are smaller

33

What are microvilli?

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

34

What make up the cytoskeleton?

Micro tubules
Micro filaments

35

What are microfilments are what are they involved in?

• protein action
• Involved in cell movement and cell division

36

What are micro tubules and what are they involved in?

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

37

What does the nucleus make?

MRNA for protein synthesis
Manufactures ribosomal RNA and ribosomes

38

What are ribosomes made up of?

Proteins and RNA

39

What is the plasma cell surface membrane?

A lipid bilayer in which proteins are embedded

40

Where is the cell surface membrane found?

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

41

What does the cell membrane do?

Regulates movement of substances in and out of the cell

42

What molecules does the cell surface membrane have?

Receptor molecules allowing it to respond to chemicals like hormones

43

What is the cell wall?

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

44

What is the function of the cell wall?

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

45

What are vesicles?

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

46

What do vesicles do?

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

47

Where are vesicles formed?

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

48

What is centriole?

Small hollow cylinders made of microtubules

49

Where are centrioles found?

In animal cells
Only in some plant cells

50

What are centrioles involved in?

The separation of chromosomes in cell division

51

What is cilia?

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

52

What does cilia look like in cross section?

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

53

What do the micro tubules in the cilia allow?

The cilia to move

54

What is the movement in cilia used for?

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

55

What are flagella?

• like cilia but longer
• they stick our from the cell surface

56

What does flagellum look like?

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

57

What makes flagellum move?

The micro tubules contract to make flagellum move

58

What is flagella used for?

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

59

What are chloroplasts?

Small flattened structures found in plant cells.

60

What does a chloroplast do?

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

61

What is the structure of chloroplasts?

• 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)

62

How big are eukaryotic cells?

10-100 micrometers

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