Biology > A2.2 Eukaryotic Cell Structure > Flashcards

A2.2 Eukaryotic Cell Structure Flashcards

(63 cards)

Study These Flashcards
1
Q

What are the two substances that the cytosleleton is made of?

A

Microtubules- tubulin
Microfilaments - actin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the two layers of the nucleus’double membrane?

A

The nuclear envelope - a phospholipid bilayer with nuclear pores
The outer membrane is continuous with the endoplasmic reticulum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the advantages of compartmentalisation?

A

Membranes provide a large surface area for the attachment of enzymes
It seperates substances that could cause damage
Organelles can be moved around in cells
Each organelle can have its own conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What’s the name of the soft granular material inside the nucleus?

A

The nucleoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What condenses to form chromosomes?

A

Chromatin - the denser areas of chromatic are called heterochromatin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the name for the flattened sacs on the endoplasmic reticulum?

A

Cisternae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the spherical body inside the nucleus called?

A

The nucleolus - which manufactures tRNA, rRNA and ribosomes.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does the rough er do?

A

The rough er is concerned with protein synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does the smooth er do?

A

The smooth er is concerned with lipid synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of ribosomes do eukaryotic cells have?

A

80s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the eukaryotic cell wall made of

A

Cellulose or chitin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Protoplasm

A

Anything outside the cell boundary, surrounded by the plasma membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does the cytoskeleton do?

A

-gives cells structure
- allows the organelles to move

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How big are nuclear pores and what so they do?

A

40-100 nanometers in diameter and they provide communication and passage of molecules in and out of the nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How many pairs of chromosomes are in humans

A

23

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what does Ribosomal rna do?

A

Carry the instructions for protein synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How big are mitochondria?

A

About 5 micrometers by 0.2 micrometers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the name of the folds of the inner membrane of mitochondria?

A

Cristae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the two layers of the mitochondria membrane separated by?

A

Inter membrane space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does the outer membrane of the mitochondria do?

A

Controls entry and exit of chemicals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What’s the middle of the mitochondria called?

A

The matrix, it’s semi-rigid containing proteins and lipids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What’s along the cristae and what do they do?

A

Stalked granules that hold enzymes for breaking down glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Do mitochondria have their own ribosomes and a small circle of DNA?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the inner membrane of chloroplasts folded into?

A

Lamellae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the space in the middle of the chloroplast called?
The stroma
26
What are the stacks of membranes in chloroplasts called and what are they made from?
Grana, made of thylakoids which contain chlorophyll so they're for light absorption and ATP synthesis
27
How are the grana connected in the chloroplasts?
Intergranal lamellae
28
What's inside the stroma?
Starch grains
29
Do chloroplasts have their own dna and ribosomes?
Yes
30
What's the chemical equation for photosynthesis?
6CO² + 6H²O --> C⁶H¹²O⁶ + 6O²
31
What does the endoplasmic reticulum do?
Helps to form the cytoplasm skeleton and allows for transport of materials -it collects and stores synthesised materials and adds structure
32
What are the cisternae of the cytoplasmic reticulum?
Flattened sacs with fluid filled spaces between them
33
How big are ribosomes?
20 nanometer diameter
34
What are the two subunits of ribosomes in eukaryotic cells?
40s and 60s subunits
35
What do ribosomes do?
They bind messenger RNA and transfer RNA to synthesise polypeptides and proteins during the process of translation.
36
What are ribosomes made of?
65% rRNA and 35%protein
37
What is the Golgi body? (Physically)
A stack of flattened membranes with fluid filled vesicles containing polypeptides
38
Proteins produced by the ER are passed through the Golgi apparatus in what sequence?
1. Through the Golgi network which returns any wrongly exported proteins to the ER. 2. Through the stack of cisternae which modify the proteins and lipids and add labels 3. The trans golgi network is where the proteins and lipids are sorted and sent to their final destinations, they may fuse with the cell membrane, secreting the proteins by exocytosis.
39
What are vesicles and what do they do?
They are membrane bags that transport proteins around the cell and are used in endocytosis and exocytosis
40
What's the name of the protein that coats vesicles to give them extra support?
Clathrin
41
What does clathrin do?
Coats vesicles for support and allows vesicles to connect to other proteins e.g. the cytoskeleton
42
How does clathrin work?
Clathrin molecules bind to the membrane and form a ball type structure- this then buds off and the clathrin is released
43
What are lysosomes?
Small, temporary vacuoles surrounded by a membrane that contain around 50 enzymes in acid solution
44
How are lysosomes formed?
By being pinched off from the golgi body
45
What do lysosomes do?
-They isolate potentially harmful digestive enzymes -They digest material which the cell consumes from the environment and absorb the useful chemicals -They digest dead organelles and breakdown cells (autophagy and aytolisis)
46
What does apoptosis mean?
Cells programed to die
47
What does exocytosis mean?
Release enzymes outside tye cell
48
What's the order of protein synthesis starting from the nucleoulus?
Nucleoulus - makes ribosomes - synthesise proteins - RER - golgi body - modifies and packages proteins- vesicles
49
How do you calculate magnification?
size of actual image / actual size
50
What are immunoflourescent stains?
Used in microscopy, antibodies that bind to a specific chemical in the cell are produced. A fluorescent marker is linked to the antibodies. Images produced of cells treated with these antibodies show the cell structure overlain with the bright colour of the flourescent marker where the specific chemical occurs in the cell. in short - improves images by adding flourescent tags to antibodies that attach specific proteins.
51
What is freeze fracture electron microscopy?
This technique is used to produce images of surfaces within cells. A sample is freezed, then a steel blade fractures the frozen sample through the weakest points of the cells. A replica of the fractured surface is created. In short - to observe inner surfaces of membranes
52
What does cryo -EM do?
allows determination of 3D structures of molecules
53
What are the cellular structures found in all organisms?
DNA as genetic material cytoplasm composed mainly of water plasma membrane composed of lipids
54
Why don't animal cells have a cell wall?
It allows them to take in food by endocytosis but it makes them vulnerable to bursting if too much water enters by osmosis
55
What are plastids?
A family of double membraned organelles e.g. chloroplasts or amyloplasts. Animal cells and fungus cells have no plastids
56
What are centrioles?
organelles used in animal cells to organise an assembly of a spindle of microtubules during mitosis and meiosis
57
What are some adaptations of skeletal muscle?
contains hundreds of nuclei (multinucleate), which allows them to produce more mRNA and therefore more protein.
58
Know how to create drawing from electron micrographs
check page 64 of study guide
59
what are polysomes
groups of ribosomes
60
What do we call the cell membrane instead of semi permeable?
selectively permeable
61
What is endosymbiosis in the case of mitochondria in cells?
A unicellular ancestor of eukaryotes (which could only respire anaerobically) engulfed a bacteria (which could respire aerobically). The bacteria divided and was passed onto daughter cells when the host cell divided until it became mitochondria. (this also applies to chloroplasts but with photosynthetic bacteria)
62
What is the evidence for endosymbiotic theory in cells?
mitochondria and chloroplasts have a loop of naked DNA, 70s ribosomes (and make some of their own proteins), reproduce by splitting in two and are double membraned.
63
What are the advantages of being multicellular?
Lifespan can be longer because the death of one cell does not prevent the continued survival of an individual larger body size is possible - useful in animals that are predators, or plants that compete for light. Cell differentiation - each cell carries out its function more effectively and more complex body forms can develop
Biology
flashcards
Decks in class (13)
# Cards
Brainscape helps you reach your goals faster, through stronger study habits.
© 2026 Bold Learning Solutions. Terms and Conditions