3.2 Cells 3.2.1.1 Structure Of Eukaryotic Cells Flashcards
(108 cards)
1
Q
What type of organelles do eukaryotic cells all contain
A
Membrane bound organelles
2
Q
What does the nucleus act as and how
E.g
A
The control centre of the cell by producing components needed for protein synthesis
E.g mRNA, tRNA, ribosomes
3
Q
What does the nucleus contain and in what form
A
Genetic material in chromosomes
4
Q
5 parts of a nucleus
A
Nuclear envelope Nuclear pore Nucleolus Nucleoplasm Chromatin
5
Q
What’s the membrane of the nuclear envelope like
A
Double membrane, phospholipid bilayer
6
Q
2 things the nuclear envelope does in a cell
A
Controls movement of substances in + out of nucleus
Helps maintain shape of nucleus
7
Q
What does nuclear pore allow
A
Allows some molecules (e.g RNA) to move between nucleus + cytoplasm
8
Q
What’s the most dense organelle in the nucleus
A
Nucleolus
9
Q
What 2 things does the nucleolus do
A
Synthesises sub-unit components of ribosomes
Makes rRNA
10
Q
When do chromosomes form
A
When the cell is dividing
11
Q
What’s the nucleoplasm
A
Granular, jelly-like substance
12
Q
What’s chromatin
What does it do
A
DNA wrapped/coiled around histones (proteins)
Controls cells activities
13
Q
What are ribosomes the site of
A
Protein synthesis
14
Q
Where are ribosomes found
A
Freely in cytoplasm
Bound to the membrane of the Endoplasmic Reticulum
15
Q
Where are ribosomes formed
What are they made up of
A
Formed in the nucleus
Made up of RNA and proteins
16
Q
Where would u find large (80s) ribosomes
A
In plant/animal cells
17
Q
What 3 places would u find small (70s) ribosomes
A
In bacterial cells, mitochondria + chloroplasts
18
Q
How do the ribosomes form proteins
A
Between the small subunit and large subunit when they combine, in a gap
19
Q
What’s the endoplasmic reticulum
A
Folded up membrane system/network
20
Q
What part of the endoplasmic reticulum are ribosomes
A
Rough (RER)
21
Q
Where does the protein transport and modifying process begin in a cell
A
The nucleolus
22
Q
What’s the RER attached to
A
The nucleus’ nuclear envelope
23
Q
What does the endoplasmic reticulum have that increases the rate of protein synthesis
A
A large surface area
24
Q
Where do the synthesised proteins by the ER go to next
A
They pass into the lumen of the ER via pores and then travel to the Golgi apparatus in vesicles
25
When do the proteins become modified
When they are in the Golgi apparatus
26
How do proteins edit the cell from the Golgi
They leave the Golgi in vesicles and then exocytosis occurs
27
What are vesicles
‘Empty’ protein sacs (filled with proteins)
28
What are the 2 types of membrane in the ER
Smooth ER
| Rough ER
29
What does the smooth ER do
Synthesises, stores + transports lipids/carbs
30
What ER is covered in ribosomes
Rough ER
31
What’s cell’s is the endoplasmic reticulum common in
E.g
Cells that make/store lots of carbs, protein/lipids
E.g liver cells, epithelial cells in small intestine
32
How do proteins travel to the Golgi apparatus
In vesicles
33
What’s the Golgi apparatus made up of
| How is this beneficial
Cisternae - flattened sacs of membrane
| Gives a larger SA
34
What does the Golgi apparatus do (3)
Modifies proteins + lipids e.g lysosomes
Adds carbohydrates to proteins (glycoproteins)
Releases modified proteins in vesicles (bulk transport)
35
What does the Golgi apparatus produce when it adds carbohydrates to proteins
Eg
Glycoproteins e.g antigens
36
What are lysosomes a form of
Modified protein released from the Golgi apparatus
37
Lysosomes have a membrane, but what do they not have
Have no specified internal structure
38
What do lysosomes contain
E.g of a cell that contains many
Up to 50 digestive enzymes that break down waste in a cell
E.g white blood cells contain lysosomes
39
4 jobs lysosomes do
Digest harmful materials ingested by WBCs
Release enzymes outside the cell for digestion
Digest worn out organelles + recycle their chemicals
Break down cells that have died
40
What’s the membrane of a lysosome like
Thick, double membrane
41
What are the membranes like in a mitochondria
(Bilayer) surrounded by 2 membranes
42
What’s the inner membrane of mitochondria folded into
Cristae
43
What does the matrix in mitochondria contain
Enzymes involved in aerobic respiration
44
What’s the cytoplasm called in mitochondria
Matrix
45
What do mitochondria synthesise
ATP (produce energy)
46
What cells are mitochondria common in
| E.g
Cells that need a lot of energy e.g muscle cells + epithelial cells
47
How can mitochondria make its own proteins + replicate alone
As it contains DNA + ribosomes
48
What on the cristae in mitochondria contains the ATP producing enzymes (ATP-ase) for respiration
Oxysomes
49
What does the plasma membrane control
What substances enter + leave cells
50
What’s a plasma membrane made up of
A phospholipid bilayer
51
2 parts of a phospholipid
```
Phosphate group (head)
Fatty acids (tails)
```
52
What part of phospholipid is hydrophilic + hydrophobic
Phosphate group - hydrophilic (loves water)
| Fatty acids - hydrophobic (hate water)
53
What’s embedded into the plasma membrane
Proteins
54
3 types of proteins embedded in plasma membrane
Ion - channel proteins
Transport proteins
Glycoproteins
55
What do ion-channel proteins allow
E.g
Allow some ions to pass through the membrane
E.g Na, K, Fe
56
What can ion-channel proteins not carry
Insoluble things (hydrophobic)
57
What do transport proteins do
Carry molecule in + out of the cell
58
What do transport proteins use
| What process are they involved in
Use ATP
| Involved in active transport
59
What’s the word for ‘in the membrane ’
Instrinsic
60
What do glycoproteins do
Act as markers so that the cell can be recognised (antigens)
61
2 things that stick out of membranes
Glycoproteins
| Glycolipids
62
How do you notice glycoproteins on membrane diagrams
They are slightly larger and are attached to proteins
63
What’s the word for ‘sticks out of membrane’
Extrinsic
64
How do glycoproteins help a group of cells
Help them attach to each other, forming cell tissue
65
What do glycolipids help to determine
Blood type
66
What are glycolipids made up of
Carbohydrates bound to lipids
67
2 ways glycolipids are helpful
Help stabilise the membrane
| Help cells attach to one another
68
How does cholesterol benefit a membrane
Adds strength (holds together tails )
69
Why does cholesterol help reduce water loss from the bilayer
As it’s very hydrophobic
70
What does having cholesterol in a membrane reduce and how
Reduces movement as it pulls together the lipid tails
71
What’s the model that shows what’s in a membrane called
The fluid mosaic model
72
Why’s it called ‘fluid’ ‘mosaic’ model
Fluid - slight flexibility as phospholipids move relative to each other
Mosaic - embedded throughout membrane
73
What’s another name for channel proteins
Channel proteins
74
What’s another name for transport proteins
Carrier proteins
75
Why are channel proteins hydrophilic
| What are they like
For water + other polar molecules to pass through
| Are like pores/holes in the membranes
76
What do carrier proteins use to open them
ATP for active transport to open them
77
What do carrier proteins have similar to enzymes
Specific binding sites for certain substances, their shape has to be complementary to a specific substance
78
What are chloroplasts in
Plants + algae
79
What system are chloroplasts not part of
The endoplasmic reticulum system
80
Why are chloroplasts independent like mitochondria
They have their own DNA + ribosomes
81
What’s the green pigment called that chloroplasts contain
| What’s it important for and why
Chlorophyll
| Important for photosynthesis as it absorbs sunlight
82
What’s 1 flattened membrane sac in a chloroplast called
| What’s a stack of them called
Thylakoid
| Granum
83
What part of chloroplasts does photosynthesis take part in
Thylakoids
84
Why are thylakoids arranges in stacks
So they are compact and more can be fitted in , so more chlorophyll, and more photosynthesis
85
What’s the fluid inside a chloroplast called that contains DNA + ribosomes
Stroma
86
What 2 things is the stroma in chloroplasts the site of
The site of chemical reactions + sugar production (food)
87
3 things the cell wall does
Protects cell
Maintains shape
Prevents excessive water uptake/loss
88
What do cell walls contain
Cellulose (sugar) , proteins + carbohydrates
89
What are the 3 layers of a cell wall
The middle lamella
The primary cell wall
The secondary cell wall
90
Which layer of the cell wall is stretchy
The middle lamella
91
What’s the middle lamella
The first layer of the cell wall formed after cell division (cell still a baby)
Is the connecting boundary
92
What’s the middle lamella made from
Pectin
| Protein
93
Why does the middle lamella allow the cell to grow
As it isn’t rigid
94
When does the primary cell wall form
After the middle lamella
95
Why is the primary cell wall more rigid than middle lamella
As it contains cellulose fibres that make it more rigid
96
2 thinks the primary cell wall contains other than cellulose
Pectin (carbohydrate)
| Glycoproteins
97
What cell wall causes the cell not to grow anymore once it’s formed
The secondary cell wall
98
When is the secondary cell wall formed
| What does it contain often
When the cell is mature
| Often contains layers
99
3 things the secondary cell wall is made up of
Cellulose
Hemicellulose
Lignin (in woody plants)
100
What’s the biggest part of a plant cell
Vacuole
101
What does a permanent vacuole contain
Cell sap
102
What’s a vacuoles single membrane called
Tonoplast
103
5 things a vacuoles fluid contains
```
Minerals
Sugars
Amino acids
Waste products
Pigments (anthocyanins)
```
104
3 uses of a vacuole
Keeps cell turgid (firm)
Stores waste products that may damage the cell
Acts as a food store
105
What do the pigments in a vacuole do
Add colour to petals
106
What type of compounds does a vacuole contain
Poisonous/unpalatable compounds
107
What’s the process called when cells can do specific functions
Specialisation
108
What are specialised cells organised into
Tissues -> organs -> organ systems
