Cell Biology Flashcards
(125 cards)
0
Q
There are four types of cells, what are they?
A
Animal.
Plant.
Bacterial.
Fungal.
1
Q
What are cells?
A
Cells are the basic units of all living organisms.
2
Q
What are organelles?
A
The different parts of a cell.
3
Q
What is the function of the cell wall?
A
Provides shape and structure.
4
Q
What is the function of mitochondria?
A
Site of aerobic respiration.
5
Q
What is the function of chloroplasts?
A
Site of photosynthesis.
6
Q
What is the function of the cell membrane?
A
Controls movement of substances in and out of a cell.
7
Q
What is the function of the cytoplasm?
A
Site of chemical reactions.
8
Q
What is the function of the vacuole?
A
Storage for water, sugars and salts.
9
Q
What is the function of the nucleus?
A
Controls cells activities and contains genetic information.
10
Q
What is the function of a ribosome?
A
Site of protein synthesis.
11
Q
What are the functions of plasmids?
A
Small circular DNA.
12
Q
What organelles does a plant cell contain?
A
Cell wall, cytoplasm, cell membrane, vacuole, nucleus, ribosome, mitochondria, chloroplasts.
13
Q
What organelles does a animal cell contain?
A
Cytoplasm, cell membrane, ribosome, nucleus, mitochondria.
14
Q
What organelles does a fungal cell contain?
A
Mitochondria, ribosomes, cell membrane, nucleus, cytoplasm, vacuole, cell wall.
15
Q
What organelles does a bacteria cell contain?
A
Cytoplasm, plasmids, cell wall, cell membrane, circular DNA, ribosomes, capsule.
16
Q
What are some uses for fungi?
A
Recycling nutrients, plant growth, food, medicines, decomposing waste and food.
17
Q
Cells walls in fungal, bacterial and plant cells are all structurally and chemical different. What is each cells wall made of?
A
Plant cell - cellulose
Fungal cell - chitin
Bacterial cell - peptidoglycan
18
Q
Cells are viewed using what?
A
A microscope.
19
Q
Stains must be added to view the part of a cell. What stain is used for plant cells?
A
Iodine solution.
20
Q
What stain is added to see animal cells clearly?
A
Methylene blue.
21
Q
Total magnification is calculated by…?
A
Eyepiece Lens x Objective Lens
22
Q
Cells are too small to be measured in millimetres (mm). What are they measured in?
A
Micrometers (μm).
23
Q
How do you calculate the average cell length?
A
Count how many cells going from one side to the other and divide by the diameter.
24
The structure of a cell membrane is described as what and why?
Described as a 'fluid mosaic model' because it is made of phospholipids and proteins.
25
What do the lipids allow the membrane to do?
To be able to move, they make the membrane fluid.
26
Some proteins have channels running through them to allow what?
To allow certain substances to pass into and out of the cell.
27
The cell membrane is described as what?
Selectively permeable.
28
The cell wall is described as what?
Fully permeable.
29
What is the concentration gradient?
The different conditions inside and outside a cell.
30
What is passive transport?
The movement of molecules from an area of high concentration to an area of low concentration, down a concentration gradient, through a selectively permeable membrane until it is evenly spread.
31
Does passive transport require energy?
No.
32
What is diffusion?
A type of passive transport which is important as it allows cells to gain raw materials for respiration and remove harmful waste products.
33
What is osmosis?
A specific type of passive transport which is the movement of water.
34
What is a hypotonic solution?
A solution where there is less solute and more water.
35
What is a hypertonic solution?
A solution where there is more solute and less water.
36
What is an isotonic solution?
A solution that has equal measures of solute and water.
37
What is the osmotic effect on a plant cell placed in a hypotonic solution?
Water goes into the cell.
Cell becomes turgid.
Cell will never burst because of cell was so will only bulge.
Cell gains weight.
38
What is the osmotic effect on a plant cell placed in a isotonic solution?
There is no water movement.
| There is no weight change.
39
What is the osmotic effect on a plant cell placed in a hypertonic solution?
Water goes out of the cell.
Cell becomes flaccid or plasmolysed.
Everything gets pulled in with vacuole.
Cell loses weight.
40
What is the osmotic effect on an animal cell when placed in a hypotonic solution?
Water moves into the cell.
| Cell bursts because of no cell wall.
41
What is the osmotic effect on an animal cell when placed in a isotonic solution?
There is no weight change.
| There is no water movement.
42
What is hen osmotic effect on an animal cell when placed in a hypertonic solution?
Water moves out of the cell.
Cell loses weight.
Cell shrinks.
43
What is active transport?
The movement of molecules from an area of high concentration to an area of low concentration, against a concentration gradient, through a selectively permeable membrane until it's evenly spread.
44
Does active transport require energy?
Yes.
45
Sodium and potassium move in and out of what cell by active transport?
A nerve cell.
46
What factor effect active transport?
Oxygen concentration.
Glucose concentration.
Temperature.
47
Sodium/potassium pumps are located in a nerve cell. Nerve cells must maintain what?
A higher concentration of sodium outside the cell and potassium inside the cell.
48
The sodium/potassium protein pump pumps sodium ions out of the cell and what ions into the cell.
Potassium ions.
49
Why do cells divide?
To form a complete copy of themselves or to produce more cells for growth and repair.
50
Cell division is controlled by what?
The nucleus of a cell.
51
Humans contain how many chromosomes?
46 chromosomes, 23 pairs.
52
All body cells have two sets of chromosomes, one from the mother and one from the father. What are these cells called?
Diploid cells.
53
The number of chromosomes a cell contains is its what?
Chromosome complement.
54
A chromosome is made of two chromatids joined at the what?
Centromere.
55
What is mitosis?
The process of a diploid cell dividing.
56
During mitosis, two daughter cells are produced which contain the same number of chromosomes as what?
The parent cell.
57
Why is it important for the daughter cells to have the same number of chromosomes as the parent cell?
So that no genetic information is lost and so that the cells can carry out the same functions as the parent cell properly.
58
What is the stages of mitosis?
1. The diploid nucleus contains long uncoiled chromosomes.
2. Each chromosome doubles to form two identical chromatids.
3. The chromosomes shorten and coil up.
4. The nuclear membrane disappears.
5. The chromosomes line up at the equator of the cell.
6. Spindle fibres attach to the centromeres.
7. The pair of individual chromatids are pulled apart by the spindle fibres to opposite poles of the cell.
8. New nuclear membranes form and the cytoplasm divides.
9. Two daughter cells have been formed each containing the same chromosome complement as the parent cell.
59
Cells can be cultured ins lab what does this mean?
The can be grown.
60
What are two small scale growth media with contains the nutrients to allow the cells to grow successfully?
Agar and broth.
61
What is an aseptic technique?
Fully sterile way of working so that there is no unwanted growth of microbes and no contamination.
62
What are autoclaves used for?
Killing resistant spores at high temperatures and pressures.
63
What is a large scale production of cells?
Using a fermenter.
64
What does optimum mean?
The conditions that allow for the best results or fastest reaction.
65
What are chromosomes made of?
DNA- deoxyribonucleic acid.
66
Where is DNA found?
In the nucleus.
67
What does DNA contain?
The genetic instructions to make proteins.
68
What is the structure of DNA described as?
A double helix.
69
What is the structure of DNA?
Two strands twisted in a helix joined by bases.
70
What is the four bases and their letters?
Adenine, A
Thymine, T
Cytosine, C
Guanine, G
71
Base pairing is said to be complementary since only certain bases can pair. Which bases pair?
A+T
| C+G
72
DNA is made of 4 things: phosphate groups, deoxyribose sugars, bases and hydrogen bonds. What is the two things that create the sugar phosphate backbone?
Deoxyribose sugars and phosphate groups.
73
What is a nucleotide?
A base, a deoxyribose sugar and a phosphate group.
PG B B PG
DS DS
Two nucleotides ^
74
A section of DNA is known as what?
A gene.
75
What does a gene code for?
A protein which determines the characteristics.
76
What are the subunits of protein?
Amino acids.
77
What codes for an amino acid?
Three bases and their order/sequence.
78
What is mRNA?
Is a copy of a DNA that carries the genetic code out of the nucleus to a ribosome to make proteins.
79
The order and shape of amino acids is assembled according to the order of the bases. Why is the order and shape of the amino acids important?
The order and shape is important as different shapes create different proteins. These proteins need to be the correct shape so that they can carry out their function successfully.
80
The order of amino acids determines the structure and function of a protein. Why?
A protein is a chain of amino acids linked together by peptide bonds.
81
What are the four main types of proteins?
Transport.
Hormones.
Enzymes.
Structural.
82
What is the function of a structural protein?
To provide flexibility, allowing tissues to resume their shape after stretching or contracting.
83
What is the function of a transport protein?
Controls entry of substances in and out of cells.
84
What is the function of a enzyme cell?
Speed up chemical reactions.
85
What is the function of a hormone protein?
Chemical messenger.
86
What is an enzyme?
A biological catalyst.
87
Enzymes are very specific and can only react with specific substrates. One type of enzyme reacts with only one type of substrates. What is this called?
The lock and key theory.
88
At low temperatures and a low pH enzymes work slowly. What happened at high temperatures and a high pH?
The enzymes will become denatured meaning the active site is destroyed and the enzyme can no longer function.
89
What is a degradation enzyme?
An enzyme that breaks down substrates.
90
Name the degradation enzyme that breaks down starch into maltose?
Amylase.
91
Name an enzyme reaction that uses the enzyme catalase?
Hydrogen Peroxide -> Oxygen + Water
92
What is the enzyme reaction for breaking down protein?
Pepsin
| Protein ---------> Petitides
93
What does lipase breakdown and into what?
Breaks down fat into fatty acids and glycerol.
94
What is a synthesis enzyme?
An enzyme that build up substrates.
95
What is the enzyme synthesis reaction?
Phosphorylase
| Glucose-1-phosphate ---------> Starch
96
What are the factors effecting enzyme activity?
Temperature.
| pH.
97
What is genetic engineering?
The deliberate modification of an organisms characteristics.
98
What is the process of genetically engineering?
1. The required gene is located on the donor chromosome.
2. The gene is removed from the chromosome using enzymes.
3. A plasmid is removed from a bacterium and is cut open using enzymes.
4. The gene is inserted into the placid and sealed using enzymes.
5. The genetically modified plasmid is inserted back into the bacterium.
6. The modified bacterium is grown in optimum conditions to produce many identical cells.
7. The product is filtered and purified for use.
99
What is the respiration equation?
```
Oxygen + Glucose
|
|
|
\/
Carbon Dioxide + Water + ATP
```
100
What is stage one of aerobic respiration?
Glycolysis.
101
Where does glycolysis take place?
The cytoplasm.
102
Is oxygen needed in glycolysis?
No.
103
What are the products of the first stage of aerobic respiration?
Pyruvic acid or pyruvate.
| 2 molecules of ATP.
104
What is the second stage of aerobic respiration?
The breakdown of Pyruvic acid.
105
Where does the second stage of aerobic respiration take place and is oxygen needed?
Oxygen is need and it takes place in the mitochondria.
106
What are the products of the breakdown of Pyruvic acid?
Carbon dioxide.
Water.
36 molecules of ATP.
107
How much ATP molecules are made in total during aerobic respiration?
38.
108
How many total molecules of ATP are made during anaerobic respiration?
2.
109
Where does anaerobic respiration take place?
The cytoplasm.
110
In animal and bacterial cells anaerobic respiration is reversible. Why?
Without oxygen pyruvic acid cannot breakdown into water and carbon dioxide. Instead it breaks down into lactic acid. When oxygen is available again the oxygen dept is repaid back to Pyruvic acid to carry on to make ATP in aerobic respiration.
111
Anaerobic respiration is also know as fermentation when it comes to plans and yeast. What is the process?
Glycolysis still happens and then the Pyruvic acid is broken down into ethanol and carbon dioxide.
112
Photosynethesis equation?
```
Carbon Dioxide + Water
|
|
|
\/
Oxygen + Glucose
```
113
Plants need chloroplasts and light energy for photosynthesis to occur. Chloroplasts have a pigment that traps light energy and converts into chemical energy called what?
Chlorophyll.
114
What are the 3 fates of glucose?
Stored as starch.
Used for respiration.
Used in plant structures for support like cellulose.
115
What does xylem transport?
Water.
116
What does phloem transport?
Dissolved sugars.
117
What is the first and second stage of photosynthesis?
The first stage is the light reaction stage.
| The second stage is the carbon fixation stage.
118
Leaf structure- what is the function of the waxy cuticle?
A waterproof layer which prevent evaporation of water vapour from upper leaf surface.
119
Leaf structure- what is the function of the upper epidermis?
Protective layer which is transparent to let light through.
120
Leaf structure- what is the function of the small vein?
Branch off main vein contain xylem which take water to lead cells and air spaces and phloem which transports carbohydrates.
121
Leaf structure- what is the function of the mesophyll?
Layers of green cells which take in carbon dioxide and give out oxygen during photosynthesis.
122
Leaf structure- what is the function of the moist air space?
Large internal surface area of moisture which carbon dioxide can dissolve before diffusing into green cells.
123
Leaf structure- what is the function of the stomata?
A pore on the lower leaf surface which allows entry of carbon dioxide and exit of water vapour.
124
Leaf structure- what is the function of the guard cell?
Pairs of cells which change shape, opening and closing the stoma pore during the day or night.
