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Biology 🌱 > Key Concepts In Biology > Flashcards

Key Concepts In Biology Flashcards

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AP® Biology flashcards Biology 101 flashcards
1
Q

What is the function of cytoplasm?

A
  • Contains dissolved nutrients and salts
  • Where most chemical reactions take place
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2
Q

What is the function of the nucleus?

A
  • Contains genetic material, including DNA
  • This controls cellular activities
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3
Q

What is the function of the cell membrane?

A
  • Permeable, allows some substances but not others
  • Controls what enters and leaves the cell
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4
Q

What is the function of mitochondria?

A
  • Contains the enzymes for respiration
  • Where most energy is released, respiration
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5
Q

What is the function of ribosomes?

A
  • Site of protein synthesis
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6
Q

What is the function of chloroplasts?

A
  • Contains green pigment called chlorophyll which absorbs light energy for photosynthesis
  • Contains the enzymes needed for photosynthesis
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7
Q

What is the function of the cell wall?

A
  • Provides structure, support and protection
  • Plant cell walls are made from cellulose
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8
Q

What is the function of the permanent vacuole?

A
  • Filled with cell sap to provide support
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9
Q

What is the function of chromosomal DNA?

A
  • Found loose in the cytoplasm, not contained in a nucleus
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10
Q

What is the function of plasmid DNA?

A
  • Small closed circles of DNA
  • Can move from one bacterium to another, giving variation
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11
Q

What is the function of the flagella?

A
  • Rotate or move in a whip-like motion to move the cell
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12
Q

How is a sperm cells adapted to its function?

A
  • Acrosome, contains enzymes to digest a way through the egg cell membrane
  • Haploid nucleus, to fuse with egg nucleus
  • Mid piece, lots of mitochondria to release energy to swim
  • Tail, enables the cell to swim
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13
Q

How is an egg cells adapted to its function?

A
  • Cytoplasm, contains nutrients for growing embryo
  • Haploid nucleus, to fuse with sperm nucleus
  • Cell membrane, changes after fertilisation by a single sperm so no more sperm can enter
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14
Q

How is a ciliated epithelial cell adapted to its function?

A
  • Cilia, on the surface to move mucus containing dirt and bacteria away from the lungs
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15
Q

What is the inverse square rule for light intensity?

A

Light intensity 🐟 1/distance^2

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16
Q

How to you test for starch using chemical reagents?

A
  • Add iodine solution
  • Negative result will be orange
  • Present will be blue/black
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17
Q

How do you test for reducing sugars using chemical reagents?

A
  • Add equal volume of Benedict’s solution to a food solution and mix
  • Heat the mixture in a 95°C water bath for a few minutes
  • The colour of the reagent/negative result will be blue
  • The colour if sugar is present will be green>orange>red depending on how much sugar is present
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18
Q

How do you test for proteins using chemical reagents?

A
  • Add an equal volume of potassium hydroxide solution to the food solution and mix
  • Add a few drops of copper sulfate solution and mix
  • The colour if the reagent/negative result will be pale blue
  • The colour if protein is present will be pale purple
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19
Q

How do you test for fats using chemical reagents?

A
  • Add an equal volume of ethanol to the food solution and shake thoroughly
  • Add water to the mixture
  • The colour of the reagent/negative result will be clear
  • The colour if fat is present will be cloudy
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20
Q

How have electron microscopes enabled scientists to develop their understanding of cells?

A
  • Allow small subcellular structures to be observed in detail
  • They could develop better explanations about how cell structure relate to its function
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21
Q

What is a milli-?

A

10^-3

/ 1000

22
Q

What is a micro-?

A

10^-6

/ 1 000 000

23
Q

What is a nano-?

A

10^-9

/ 1 000 000 000

24
Q

What is a pico-?

A

10^-12

/ 1 000 000 000 000

25
Q

What are the steps to using a light microscope?

A
  • Collect a small specimen of cells with correct equipment
  • Add a drop of water or stain to the centre of the slide
  • Place your specimen on the drop of water or stain
  • Lower a cover slip onto the specimen
  • Start with the lowest magnification and work up at the higher
26
Q

Why is the water or stain used?

A

Water - prevents the specimen from drying out

Stain – allows us to see otherwise colourless parts

27
Q

Why is it cover slip used?

A

To minimise the chance of air bubbles which make it difficult to see the specimen

28
Q

Why do you start with the lowest magnification and move to a higher one?

A

Lowest – allows us to find a specimen on the slide and focus

Higher – you don’t need to use the coarse focusing wheel

29
Q

What are the rules for scientific drawings?

A
  • Smooth lines
  • No shading
  • Lines to label, no arrows
  • Keep the relative sizes of structures approximately correct
  • For microscope, write magnification next to it
30
Q

What are enzymes?

A
  • Biological catalysts
  • That speed up chemical reactions in the body
31
Q

What is the active site of an enzyme?

A

The part that a specific substrate can attach or fit into

32
Q

What are the steps of enzymes catalysing substrates?

A
  • Substrate collides with active site of enzyme and becomes attached
  • Enzyme catalyses breakdown of substrate
  • Products released from active site
33
Q

What is enzyme specificity?

A

Enzymes can only bind to a substrate with a complimentary shape

34
Q

What factors affect the activity of enzymes?

A
  • Temperature
  • Substrate concentration
  • pH
35
Q

What happens when an enzyme is denatured?

A

The shape of its active site may change so the substrate will no longer fit into the enzymes

36
Q

What effect does temperature have on enzyme activity?

A
  • As temperature increases, molecules move quicker and collide more
  • So more complexes form and rate of reaction increases
  • At optimum temperature enzymes have the fastest rate
  • Higher temperatures cause the active site to change shape so no more complexes can form, becomes denatured
37
Q

What effect does pH have an enzyme activity?

A
  • Have an optimum pH
  • If the pH shifts from the optimum the active site will change shape and it will become denatured
38
Q

How does substrate concentration affect enzyme activity?

A
  • As concentration increases, there are more particles in the same volume
  • So more collisions happen and more complexes form
  • Rate of reaction increases until all active sites become full, it then plateaus
39
Q

How do you calculate the rate of reaction of enzymes?

A

Amount of substrate used or amount of product formed
/
Time taken

40
Q

How do you investigate the effect of pH on amylase activity?

A
  • Set of heating apparatus
  • Heat the water to 40° C and maintain
  • Drop of iodine solution into each spot of spotting tile
  • Add 2 cm³ of amylase solution to a tube
  • Add 1 cm³ of a pH solution
  • Add 2 cm³ of starch solution and place into water bath
  • Every 20 seconds, place a drop of mixture on a fresh drop of iodine solution
  • Stop testing when iodine solution stops changing colour
  • Record time taken
  • Repeat with different pH solutions
41
Q

Which enzyme convert carbohydrates into simple sugars?

A

Carbohydrase enzymes

42
Q

Which enzyme converts proteins into amino acids?

A

Protease enzymes

43
Q

Which enzymes convert lipids into fatty acids and glycerol?

A

Lipase enzymes

44
Q

Why do enzymes break larger molecules into smaller molecules?

A

The large molecules are too large to pass from the intestine into the blood

45
Q

Why do some enzymes synthesise larger molecules from smaller molecules?

A

Large molecules are used for storage or to build structures

46
Q

What is calorimetry?

A
  • A way to measure the energy taken in and given out during a chemical reaction
  • Used to measure the amount of calories in food
47
Q

How would you measure the amount of energy in a sample of food?

A
  • Record the initial temperature of a set volume of water in a boiling tube
  • Set the food alight using a Bunsen flame then immediately place under the tube
  • Measure the maximum temperature of the water
  • Calculate the change in temperature
48
Q

How would you calculate the energy in food?

A

Energy in food = Mass of water (g) x Temperature change of water (°C) x 4.2

49
Q

How do you investigate osmosis using potatoes?

A
  • Set up boiling tubes each with a different sucrose solution (0%, 20%, 40%, 100%) and label
  • Cut potato into small equal-sized discs then remove excess water with tissue
  • Measured initial mass of each disc
  • Place in each of the solutions for 20min
  • Remove the potato and dry with tissue then record the mass again
  • Repeat the whole process with different discs of potato
50
Q

How do you calculate the percentage change in mass?

A

Change in mass / Initial mass
x 100%

Biology 🌱 (9 decks)

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