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Biology OCR A > Module 2 > Flashcards

Module 2 Flashcards

(102 cards)

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1
Q

What are prokaryotic cells?

A

Single celled organisms that are small and simple

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2
Q

What are eukaryotic cells?

A

Complex and include all plant and animal cells

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3
Q

What is the function of the plasma membrane?

A

Regulates movements of substances in and out of the cell

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4
Q

What is the function of the cell wall?

A

Supports plant cells

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5
Q

What is the function of the nucleus?

A

Contains chromatin and the nucleolus

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6
Q

What is the function of the lysosomes?

A

Contains digestive enzymes to digest invading cells and break down worn out cell components

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7
Q

What is the function of ribosomes?

A

Making of proteins

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8
Q

What is the function of RER?

A

Folds and processes proteins

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9
Q

What is the function of SER?

A

Synthesises and processes lipids

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10
Q

What is the function of a vesicle?

A

Transports substances in and out of the cell and between organelles

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11
Q

What is the function of the Golgi apparatus?

A

Processes and packages new lipids, makes lysosomes

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12
Q

What is the function of the mitochondrion?

A

Contains enzymes for respiration, site of aerobic respiration

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13
Q

What is the function of the chloroplast?

A

Photosynthesis

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14
Q

What is the function of a centriole?

A

Used in the separation of chromosomes during cell division

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15
Q

What is the function of cilia?

A

Allow movement of substances along the cell membrane

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16
Q

What is the function of the flagellum?

A

Outboard motors that help the cell move

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17
Q

Process of protein production:

A

1 protein made at ribosome
2 RER ribosomes make proteins that are excreted or attached to the cell
3 free ribosomes make proteins that stay in the cytoplasm
4 new proteins are folded and processed at the RER
5 transported from the RER to Golgi Apparatus in vesicles
6 proteins are further processes and packaged by the Golgi
7 proteins enter more vesicles to be transported around the cell
8 IF being secreted the vesicle fuses with the plasma membrane and the protein leaves via exocytosis

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18
Q

What are microfillaments?

A

Small solid strands

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19
Q

What are Microtubules?

A

Tiny protein cylinders

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20
Q

4 main functions of the cytoskeleton

A

1 support the cells organelles, keeping them in positions
2 strengthen the cell and maintain its shape
3 responsible for movement of materials within the cell
4 proteins of the cytoskeleton can also cause the cell to move - cytoskeleton propels the cell eg flagellum

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21
Q

DNA in prokaryotes is…

A

Circular

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22
Q

DNA in eukaryotes is…

A

Linear

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23
Q

Prokaryotes are less than …. in diameter

A

2 micrometers

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24
Q

Eukaryotes are normally ….. in diameter

A

10-100 micrometers

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25
Do prokaryotes have a nucleus?
No, dna is free in the cytoplasm
26
Do eukaryotes have a nucleus?
Yes, dna is inside the nucleus
27
Do prokaryotes have a cell wall?
Yes, but not chitin or cellulose
28
Do eukaryotes have a cell wall?
No cell wall, plant cells have a cellulose cell wall
29
Do prokaryotes have membrane bound organelles?
No, they have very few organelles and no membrane bound
30
Do eukaryotes have organelles?
Yes, they have many inc,using membrane bound organelles
31
What is the flagella made from in prokaryotes?
Flagellin, arranged in a helix
32
What is the flagella in eukaryotes made of?
Microtubule proteins in 9+2 formation
33
Prokaryotes have .... ribosomes
Small
34
Eukaryotes have ..... ribosomes
Large
35
An example of a prokaryote is....
E.Coli Bacterium
36
An example of a eukaryote is....
Human liver cell
37
What size are bacteria?
Roughly 1 10th of the size of a eukaryotic cell
38
Bacteria can be seen under a .... microscope
Electron
39
A bacterial cell contains what 6 things?
``` Flagellum DNA Plasma membrane Cell wall Plasmid Ribosomes ```
40
Define magnification
How much bigger the image is than the sample you are looking at
41
Define resolution
How detailed the image is - the ability to distinguish between two points that are close together
42
What is the formula for magnification?
Magnification = image / actual
43
What is the resolution and magnification of a light microscope ?
0.2 micrometers | X1500
44
What type of specimens can light microscopes look at?
Dead and Alive
45
How does a laser scanning confocal microscope work?
Uses laser beams to scan specimen that is tagged with a fluorescent dye Laser causes the dye to fluoresce and give off light Light is focused through a pinhole onto a detector, hooked up to a computer which produces an image - can be 3D Any out of focus light is blocked = clearer image
46
How does a TEM work
Electromagnets to focus beams of electrons - transmitted through specimen Denser parts absorb more electrons which make them darker on image Provide high resolution images - organelles can be seen
47
How does SEM work
Scan beams of electrons across specimen Knocks off electrons from specimen which is gathered in cathode tube to form an image 3D image
48
What is the magnification and resolution of a TEM
0.0002 micrometers | X1000000
49
What is the magnification and resolution of a SEM
0.002 micrometers | X500000
50
What stain is used with light microscopes?
Methylene blue or eosin
51
What does eosin stain?
Cell cytoplasm
52
What does methylene blue stain?
DNA
53
What are objects dipped in for electron microscopes?
Heavy metals such as lead, the metal ions then scatter electrons creating contrast
54
How do you prepare a dry mount?
Thin slice of specimen Tweeters to place in middle of the slide Tilt and lower the cover slip
55
How do you prepare a wet mount?
Pipette a small drop of water Tweezers to place specimen in the middle Tilt and lower the cover slip, avoiding air bubbles Stain by placing a drop of stain on one side and place paper towel on opposite side Stain will get drawn through
56
How to use a light microscope?
Clip slide to the stage Lowest powered objective lens Coarse adjustment knob to bring up stage to lens Look down ocular lens and use coarse adjustment to focus on specimen Adjust focus with fine adjustment knob until image is clear Greater magnification = swap to a higher objective lens and refocus
57
An eyepiece graticule has .... units
No units
58
Stage micrometers have a .... scale
Accurate scale
59
What percentage of the cells contents is water
80%
60
What are the 5 functions of water?
``` Reactant Solvent Transport Temperature control Habitat ```
61
Water has a .... structure and can partake in ..... bonding
Simple and hydrogen
62
What are the 4 Properties of water?
High specific heat capacity High latent of evaporation Cohesive and good solvent Less dense when a solid
63
What are all carbohydrates made of?
Carbon, hydrogen and oxygen
64
Glucose is what type of sugar?
Hexose , alpha and beta
65
Ribose is what type of sugar?
Pentode sugar, sugar component of RNA
66
What bonds join monosaccharides to form disaccharides and polysaccharides ?
Glycosidic bonds, using condensation reactions
67
How are these glycosidic bonds broken?
Hydrolysis
68
Examples of disaccharides
Maltose - two alpha glucose Sucrose -alpha glucose and fructose Lactose - alpha/beta glucose and galactose
69
Example of polysaccharides
Amylose - alpha glucose
70
What is Starch used for in plants?
Energy storage
71
Amylose
Long, unbranded chains of alpha glucose in coiled structure | Good for storage as more compact
72
Amylopectin
Long, unbranded chains of alpha glucose | side branches allow enzymes that break down the molecule = easy access
73
Glycogen
Main energy storage in animals Alpha glucose Side branches - released quickly Compact - good for storage
74
Cellulose
Long unbranched chains of beta glucose Straight cellulose chains Linked together by hydrogen bonds - microbfibrils = structural support
75
Triglycerides
Macromolecules One molecule of glycerol with 3 fatty acids Contain Ester bonds
76
Saturated
No double bonds between carbons
77
Unsaturated
At least one double bond between carbons
78
Properties and functions of triglycerides
Long hydrocarbon tail - chemical energy released when broken down; twice as much as carbohydrate, insoluble
79
Properties and functions of phospholipids
Hydrophilic head and hydrophobic tail form double layer, water soluble substances can’t pass through easily - barrier
80
Properties and functions of cholesterol
Small size and flattened shape, fit between phospholipid molecules and bind to hydrophobic tails, membrane more rigid, less fluid
81
Proteins are .....
Polymers
82
Amino acids are .....
Monomers
83
Dipeptide
Two amino acids joined by peptide bond
84
Polypeptides are
More than two amino acids joined together
85
Amino acids contain...
Amino group, variable group, carboxyl group
86
Primary structure of proteins
Sequence of amino acids in a polypeptide | Peptide bonds
87
Secondary proteins
Hydrogen bonds form between near amino acids and coil into a alpha helix or beta pleated sheet Hydrogen bonds
88
Tertiary structure
Coiled and folded further, more bonds form between parts of polypeptide chain, final 3D structure Ionic bonds, disulphides bridges, hydrophobic/hydrophilic interactions, hydrogen bonds
89
Quarternary structure
Several different polypeptide chains held together by bonds, for proteins with more than 1 polypeptide chain Bonds determined by tertiary bonds present
90
What happens if you heat a protein
Break up ionic and hydrogen bonds, change in 3D shape
91
Globular proteins
Hydrophilic R groups on outside of molecule, soluble, easily transported in fluids
92
Examples of globular proteins
Haemoglobin Insulin Amylase
93
Fibrous proteins
Insoluble and strong, structural and fairly unreactive
94
Examples of fibrous proteins
Collagen Keratin Elastin
95
Inorganic ions
Important in biological processes
96
Anions
``` Calcium Sodium Potassium Hydrogen Ammonium ```
97
Cations
``` Nitrate Hydrogencarbonate Chloride Phosphate Hydroxide ```
98
Benedicts test
Reducing sugars - all monosaccharides and some disaccharides Add benedicts always use excess Heat in water bath until boil Precipitate brick red = positive NON reducing sugars Add dilute HCl and carefully heat, neutralise with sodium carbonate Carry out benedicts
99
Test strips for glucose
Coated in reagent, compare to chart | Eg diabetes, infections etc
100
Iodine test for starch
Potassium iodide solution Add to sample Positive = blue black
101
Biuret test for proteins
Colours are pale so look carefully Has to be alkaline so as NaOH Add copper sulphate Protein = purple
102
Emulsion test for lipids
Shake test solution with ethanol for 1 min Pour solution into water Milky if lipid present

Biology OCR A (1 decks)

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