Cells Flashcards
(150 cards)
1
Q
What organelles does the animal cell have?
A
Nucleus Plasma membrane Cytoplasm Ribosomes Smooth endoplasmic recticulum Mitochondria Golgi apparatus Vesicles Rough endoplasmic recticulum
2
Q
What makes up the animal cell’s nucleus?
A
Nuclear envelopes
Nucleolus
Nucleoplasm
3
Q
What is the function of the nucleus?
A
Controls the cell and contains the genetic material
4
Q
What is the structure of ribosomes?
A
Made of two sub units- one large and small
Contains ribosomal RNA and protein
5
Q
What are the two types of ribosomes?
A
80S- Larger
70S- Smaller
6
Q
What is the function of ribsomes?
A
Site of protein synthesis
7
Q
What is the structure of mitochondria?
A
Double membrane
Strand of DNA
8
Q
What are the outer and inner parts of the mitochondria membrane called?
A
Outer- matrix
Inner- cristae
9
Q
What is the function of mitochondria?
A
Releases energy for the cell through respiration
10
Q
What is the structure of the cell membrane?
A
Phospholipid bi-layer
11
Q
What is the function of the cell membrane?
A
Controls what moves in and out of the cell
12
Q
What is the structure of the RER?
A
Ribosomes are present
13
Q
What is the function of the RER?
A
Site of protein synthesis
Transport of materials
14
Q
What is the structure of golgi apparatus?
A
Stack of membranes containing vesicles
15
Q
What is the function of golgi apparatus?
A
Transport, modify and store proteins and lipids from the ER
Produce lysosomes and secretory enzymes
16
Q
What is the structure of SER?
A
No ribosomes
17
Q
What is the function of SER?
A
Synthesise, store and transport lipids and carbohydrates
18
Q
What is the function of cytoplasm?
A
Where chemical reactions happen for life to occur
19
Q
What is the structure of lysosomes?
A
Contains up to 50 enzymes
Membrane
20
Q
What is the function of lysosomes?
A
Remove useless/dangerous materials
21
Q
What is the function of chloroplasts?
A
Help with photosynthesis
22
Q
What is the function of the vacuole?
A
Keeps the cell rigid
23
Q
What is the structure of the cell wall?
A
Made of cellulose
24
Q
What is the function of the cell wall?
A
Provides the cell with strength and structure
25
What is a eukaryote?
A cell with a true nucleus with a nuclear envelope (membrane) surrounding chromosomes and membrane - bound organelles
26
What is a prokaryote?
A cell that lacks membrane- bound nucleus or any other membrane bound organelles
27
What type of DNA does prokaryotes have
Single stranded and circular DNA
28
What is the difference between prokaryotic DNA to eukaryotic DNA?
It's not stored in a nucleus and it;s not associated with histones
29
What is the difference between prokaryotic organelles to eukaryotic organelles?
They aren't membrane bound organelles
30
What is the difference between prokaryotic ribosomes to eukaryotic ribosomes?
They have 70S ribosomes
31
What is the difference between prokaryotic cell wall to eukaryotic cell wall?
Bacterial cell wall is made from murein whereas a eukaryote's is made from cellulose
32
What is the difference between prokaryotic capsule to eukaryotic capsule?
Some have them but eukaryotes don't
33
What is the difference between prokaryotic size to eukaryotic size?
They are smaller
34
What is the size of a prokaryote?
0.1 to 5.0 nano meters
35
What is the size of a Eukaryote?
10 to 100 nano meters
36
Why is prokaryotic DNA more simple?
So it can multiply quicker and adapt to new environments quicker
37
How many nano meters in a millimetre?
1000
38
Why might bacterial cells evolved from mitochondria and chloroplasts?
Similar size and shape
70S ribosomes
Own strand of DNA
39
How do antibiotics work without harming your other cells?
They attack parts of bacterial cells that other cells don't have, for example cell wall, 70S ribosomes and certain enzymes found in prokaryotes
40
What is the function of the capsule?
Protection
41
What is a virus?
A microscopic intracellular parasite organism that infects other organisms
42
What is the structure of a virus?
```
CD4 proteins on surface
Phospholipid membrane
Matrix
Capsid
Viral RNA
Viral enzymes
```
43
What are the enzymes found in the virus?
Reverse transcriptase
Intergrase
Protease
44
What do viruses rely on to replicate?
Introducing their own DNA into the host cell
45
How do viruses replicate?
Enters bloodstream
Protein binds to CD4 on T-helper cells
Capsid fuses with cell membrane
RNA and enzymes enter T-helper cell
Reverse transcriptase converts virus RNA to DNA
DNA enters nucleus and inserts into host's DNA
Creates mRNA using cells enzymes to make viral proteins
mRNA moves out through nuclear pores
Protein synthesis to make proteins
Breaks away from T-helper to infect other cells
46
What is magnification?
The act or process of enlarging the physical appearance or image of something
47
What is resolution?
The minimum distance apart two objects can be in order to appear as separate items
48
What are the three types of microscopes?
Light
Scanning electron
Transmission electron
49
What is the advantages and disadvantages of a light microscope?
Cheap -A
Easy to prepare -A
Poor resolution -D
Cannot see smaller organelles -D
50
What are the advantages of a TEM?
High resolution
| High magnification
51
What are the disadvantages of a TEM?
Expensive
No colour/ 2D image
Stained with heavy metal
Vacuum
52
What are the advantages of a SEM?
3D image and colour
High magnification
High resolution
53
What are the disadvantages of a SEM?
Lower resolution than TEM
Stained with gold
Specimen must be dead
Vacuum
54
Why do electron microscopes have a better resolution?
Because they have a shorter wavelength
55
What is the equation for magnification?
Image/actual size
56
How do you get from mm to micrometers?
x1000
57
How do you get from micrometres to nano meters?
x1000
58
How do you find out the total magnification when using a microscope?
Magnification of eyepiece X magnification of objective lens
59
What is cell fractionation?
The process where cells are broken up and the different organelles they contain are separated out
60
What must a buffered solution?
Ice cold
Buffered (same pH)
Isotonic
61
Why must it be ice cold?
Slow down enzyme activity
62
Why must it be buffered?
Maintain the same pH to prevent proteins from denaturing
63
Why must it be isotonic?
Same water potential as cytoplasm to prevent osmosis
64
What is a buffered solution used for?
The purpose of breaking open cells so that the organelles do not become damaged
65
Describe the process of cell fractionation
Tissue is cut up and kept in cold, buffered solution
Further broken down by homogeniser
It is spun in an ultra-centrifuge at low speed for 10mins
Spun at medium speed
Spun at high speed
66
Why is it filtered?
To remove debris, damaged organelles or non-broken down cells
67
What is the cell cycle?
A regular cycle of cell division, separated by periods of cell growth
68
What are the three main stages of cell division?
Interphase
Nuclear division
Cytokinesis
69
What are the stages of the cell cycle?
```
Growth of the cell
Synthesis of DNA
DNA replication
Replication of organelles/prepare cell for cell division
Mitosis
Cytokinesis
```
70
What is the equation for mitotic index?
No. of actively dividing cells in field view
----------------------------------------------------------- X100
Total no. of cells in field view
71
What is mitotic index?
The ratio between the number of cells in a population undergoing mitosis, to the total number of cells
72
How do cancer treatments disrupt the cell cycle?
Prevent DNA from replicating
| Inhibit metaphase, by inhibiting formation of spindle fibres
73
What is the problem with cancer treatments?
It kills all rapidly dividing cells
74
What are the stages of mitosis?
Prophase
Metaphase
Anaphase
Telophase
75
What happens in prophase?
Nuclear membrane breaks down
| Chromosomes condense and become visible
76
What happens in metaphase?
Chromosomes line up along the equator
| Spindle fibres form
77
What happens in anaphase?
Microtubles shorten pulling apart sister chromatid
| Pulled to the poles
78
What happens in telophase?
New nuclear membranes form
| Chromosomes decondense = become larger, thinner + less visible
79
What happens after mitosis?
Cytokinesis
Membrane divides
Two daughter cells
Have own nucleus
80
What is binary fission?
Asexual
81
What are the stages of binary fission?
DNA replication
Segregation
Formation of membrane
New cell wall
82
What happens in the DNA replication stage?
DNA uncoils and replicates
83
What happens in the segregation stage?
Replicated DNA moves to opposite ends
| Causes cell to elongate
84
What happens in the formation of membrane stage?
The equatorial plate separates plasma membrane
85
What happens in the new cell wall stage?
New cell wall separates it into two cells
86
What is formed in binary fission?
Two genetically identical cells (clones)
87
Why can bacteria divide easily?
No nuclear envelope
No membrane bound organelles
Free floating DNA
Single stranded DNA
88
What are the similarities between binary fission and mitosis?
```
Produce two identical daughter cells
Asexual
DNA pulled to poles
DNA replication
Cytokinesis
```
89
What are the differences between binary fission and mitosis?
New cell wall doesn't form in M
Spindle fibres don't form in BF
New nuclear envelope doesn't form in BF
Replication of plasmids doesn't occur in M
90
What does the majority of prokaryotic DNA contain?
Only one copy of each gene (haploid)
91
What does the majority of eukaryotic DNA contain?
Two copies of each gene (diploid)
92
Is there repetitive DNA in prokaryotes?
No because it is efficient and compact
93
Where does prokaryotic DNA condense?
Nucleoid
94
Where does eukaryotic DNA condense?
Nucleus
95
What is diffusion?
The net movement of particles from a high to low concentration, down a concentration gradient, until equilibrium is met
96
What are the factors of diffusion?
Temperature
Surface area
Concentration gradient
97
What is Fick's law?
Rate of diffusion (directionally proportional sign)
SA X conc gradient
------------------------------
Lemgth of diffusion pathway
98
What is the other type of diffusion?
Faciliated diffusion
99
What does the graph look like for rate of faciliated diffusion plotted against conc of glucose?
It increases then plateaus
100
Why does the graph plateau?
Because all carrier proteins have become saturated so the rate fo diffusion has reached its maximum point
101
Why are faciliated diffusion different?
Because the ions/molecules have a specific shape so they travel through intinsic proteins that are specific to the certain molecules
102
What are the similarities between faciliated diffusion and diffusion?
Passive
| High to low concentration
103
What is osmosis?
The movement of water molecules from a region of high water potential to a region of lower water potential, through a partially permeable memebrane
104
What is water potential measured in?
kPa
105
What is the water potential of water potential?
0.0kPa
106
How is water potential created?
The pressure created by water molecules
107
What does a lower water potential reveal?
It is more concentrated
108
Where will water always move to?
To the solution that is more negative (lower)
109
What is the water potential when it is further from zero?
Lower water potential
110
What is hypertonic?
Conc of solute in the solution surrounding the cell is high than inside of the cell
111
What happens if you have a hypertonic condition?
Water moves out of the cell as the solution has a lower water potential
112
What is isotonic?
Conc of solute in the solution surrounding the cell is the same as inside of the cell
113
What happens if you have isotonic conditons?
No movement of water
114
What is hyportonic?
Conc of solute in solution surrounding the cell is lower than inside of the cell
115
What happens if you have hyportonic conditions?
Water moves into the cell as the solution inside of the cell has a lower water potential
116
What happens to an animal cell in hypertonic conditions?
Shrivels
117
What happens to an animal cell in hyportonic conditions?
Lysed
118
What happens to an animal cell in isotonic conditions?
Normal
119
What happens to a plant cell in hypertonic conditions?
Plasmolyzed
120
What happens to a plant cell in hyportonic conditions?
Turgid
121
What happens to a plant cell in isotonic conditions?
Flaccid
122
Describe the cell membrane
It has a phospholipid bi-layer, that is free to move, and embedded glycoproteins
123
What is the structure of the cell membrane like?
A mosaic of different components
124
Is the cell membrane permeable?
Yes, it is relatively permeable
125
What are molecules that can pass through the cell membrane?
Lipid- soluble substances
eg. O2 and CO2
Fatty acids
126
What are molecules that can't pass through the cell membrane?
Large molecules
eg. glucose
Water soluble ions
Polar (electronically charged molecules)
127
Why can't water soluble ions pass through the cell membrane?
Because of its hydrophobic tails
128
What is the phospholipid bi-layer?
Overall structure and main barrier to prevent passage of certain molecules
129
What is cholestrol?
Hydrophobic molecules that increases the strength of te membrane and reduces fluidity
130
What is intrinsic proteins?
Transport across the membrane all the way through
131
What is a glycolipid?
Lipid with a carbohydrate chain that helpes in cell recognition
132
What is a glycoprotein?
Protein attached toa carbohydrate chain that helps in cell recognition
133
What is active transport?
The movement of substances from a low to high concentration, against a conc gradient
134
Describe active transport
Solute binds to carrier protein
ATP attaches to carrier protein + donates phosphate group
Addition of phosphate changes protein tertiary structure
Ion released + moves against conc gradient
Phosphate group leaves = proteins returns to original shape
135
What are the main features of active transport?
Against conc gradient
Requires ATP from respiration
Requires carrier proteins
136
What is a channel protein?
Water filled tubes
137
What do channel proteins provide?
Hydrophillic channels for soluble + polar ions/molecules
138
What processes are channel proteins involved in?
Facilitated diffusion
139
What type of molecules do channel proteins open for?
Specific ions
140
What processes are carrier proteins involved in?
Facilitated diffusion + active transport
141
What do carrier proteins do?
Change shape to move molecules across the membrane
142
What type of molecules do carrier proteins move?
Large specific molecules/ions
143
Describe the sodium potassium pump
3 Na+ bind using ATP
Pi binds = changes shape of tertiary structure
3 Na+ released out of the cell
High affinity for K
2 K2+ bind
Pi dissociates = changes shape = 2 K2+ released into the cell
144
What is co-transport?
The coupled movement of one molecules with its concentration gradient and another molecule against its conc gradient
145
Describe co-transport (indirect active transport)
Na+ actively transported out of the cell using NA+K pump
High conc of Na+ inside lumen so lower conc in cell
Na+ diffuses (facilitated) using different transport protein
Transport protein also carriers glucose/amino acid
146
What is the ileum?
Very end of the small intestine
147
What moves through the ileum?
Products of digestion that are not absorbed and will be excreted
148
How is the ileum adapted?
Has villi
Epithelial cells that line the cell wall have microvilli
So has a high SA
149
Why is it important that the ileum has a high SA?
So there is more space on the membrane for insertion of channel/carrier proteins
So likelihood of saturation is decreased
150
What are the cell adaptations?
Increased no. of channel/carrier proteins = less chance to be saturated
Increased SA = greater sized surface to cross
Increased mitochondria = release energy
