Biology - Topic 1 - Key Concepts in Biology Flashcards Preview

GCSE Science Edexcel 2016 Onwards > Biology - Topic 1 - Key Concepts in Biology > Flashcards

Flashcards in Biology - Topic 1 - Key Concepts in Biology Deck (74)
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1
Q

Whatdoesamicroscopedo?

A

makessmallobjectsappearlarger/magnifiessmallobjects

2
Q

Whatpartofamicroscopedoyoulookthrough?

A

eyepiecelens

3
Q

Whichpartofamicroscopedoyouusetogetaclearimage?

A

thefocusingwheel

4
Q

Puttheseinorderofsize,biggestfirst:atom,animalcell,cellnucleus,muscletissue,proteinmolecule,watermolecule

A

muscletissue,animalcell,cellnucleus,proteinmolecule,watermolecule,atom

5
Q

Amicroscopehasa×5eyepiecelensanda×5objectivelens.Whatisthetotalmagnification?

A

×25;5×5=25

6
Q

Ahumanhairhasawidthof100µmbutappears20mmwideinaphoto.Whatmagnificationisthephoto?

A

×200;20mm=20000µm;20000÷100=200

7
Q

Howmanymillimetresarethereinametre?

A

1000

8
Q

Whatunitis1000timessmallerthanamillimetre?

A

micrometre,µm

9
Q

Whatistheunitsymbolforananometre?

A

nm

10
Q

Name one part you could find in a plant cell but not an animal cell.

A

cell wall, chloroplasts, permanent vacuole

11
Q

What process happens in a mitochondrion?

A

aerobic respiration

12
Q

What is one function of a plant cell’s permanent vacuole?

A

to help keep the cell rigid/to store substances

13
Q

In which part of a plant cell is cell sap stored?

A

vacuole

14
Q

In which part of a cell would you find chromosomes?

A

nucleus

15
Q

When you look down a microscope, what is the area that you see called?

A

field of view

16
Q

Why can an electron microscope detect smaller structures in cells than a light microscope?

A

it has better magnification and better resolution

17
Q

What is a picture taken with a microscope called?

A

micrograph

18
Q

Some microscope pictures have a small line drawn on them with information about how long the line is when unmagnified. What is this line called?

A

scale bar

19
Q

List three sub-cellular structures that are usually

found in animal cells.

A

cell membrane, nucleus, mitochondria, ribosomes

20
Q

Which cell structure controls what enters and leaves the cell?

A

cell membrane

21
Q

Which cell structure controls how the cell works?

A

nucleus

22
Q

Which plant cell structure contains chlorophyll?

A

chloroplast

23
Q

What is the function of the cell structure that contains chlorophyll?

A

to capture energy from light for photosynthesis/to produce glucose using photosynthesis

24
Q

Describe the function of the cell wall

A

supports and protects the cell

25
Q

What is the function of ribosomes?

A

manufacture of proteins

26
Q

What are gametes?

A

sex cells

27
Q

A bacterium is 20 µm long. How long is it in metres?

A

0.00002 m

28
Q

A bacterium is 5 µm wide. How wide is it in nanometres?

A

5000nm

29
Q

What do bacteria use to move themselves?

A

flagella

30
Q

Animal and plant cells are eukaryotic. What word describes bacterial cells?

A

prokaryotic

31
Q

Name one structure that an animal cell would have but a bacterial cell would not.

A

nucleus, mitochondria

32
Q

What is 1 × 10^6m written as an ordinary number?

A

1 000 000 m

33
Q

Name two substances that might be found in the cytoplasm of an egg cell to provide energy.

A

carbohydrate or starch, lipid or fat or oil

34
Q

In which system of the body is food broken down?

A

digestive system

35
Q

Why do we need to break food down?

A

because the molecules in food are too large to cross cell membranes

36
Q

In which organ of the body is digested food absorbed?

A

small intestine

37
Q

Which group of molecules help to digest food?

A

enzymes

38
Q

Name an example of an enzyme

A

amylase, protease, lipase

39
Q

What does a sperm cell use enzymes for?

A

to digest a path through the jelly coat of the egg cell

40
Q

Do plants contain enzymes?

A

yes – they control many reactions inside plant cells

41
Q

Name a part of a plant where you might find

enzymes.

A

anywhere a reaction takes place, e.g. in chloroplasts for photosynthesis, in mitochondria for respiration, where starch grains are made

42
Q

What nutrient is starch an example of?

A

carbohydrate

43
Q

Why are proteins and carbohydrates examples of polymers?

A

They are made up of many similar molecules/monomers.

44
Q

Which monomers make up starch?

A

glucose

45
Q

Which monomers make up a protein?

A

amino acids

46
Q

Are enzymes carbohydrates, proteins or lipids?

A

proteins

47
Q

Which group of substances are fats and oils examples of?

A

lipids

48
Q

Name one food that contains a lot of starch.

A

potato, pasta, bread, rice

49
Q

What effect does the enzyme amylase have on starch?

A

breaks it down to small sugars

50
Q

Food provides nutrients for growth. What else is it a source of, which we need for activity?

A

energy

51
Q

What are the subunits (small molecules) that make up carbohydrates?

A

simple sugars, e.g. glucose

52
Q

Which two kinds of subunits form lipids (fats and oils)?

A

fatty acids and glycerol

53
Q

Which subunits make up enzymes?

A

amino acids

54
Q

Amylase is a kind of enzyme. Where is it found?

A

mouth/salivary glands and small intestine/pancreas

55
Q

Why are enzymes called biological catalysts?

A

They are molecules found inside living organisms that speed up the rate of reactions.

56
Q

What is a substrate?

A

A molecule that is changed in a reaction

57
Q

What is the substrate for amylase?

A

starch

58
Q

Starch synthase is an enzyme that catalyses the synthesis of starch. Explain what this means.

A

The enzyme combines with subunits/small sugar molecules and helps them join together to form starch.

59
Q

Why do different enzymes have different 3D shapes?

A

The amino acids are arranged in a different order in different proteins.

60
Q

Which kind of large organic molecule does a protease digest?

A

proteins

61
Q

What is the name of the part of an enzyme into which the substrate fits?

A

active site

62
Q

Why do most enzymes only work with one

substrate?

A

Only substrates with the same shape as the active site can sit in the site and take part in the reaction.

63
Q

Enzymes are specific to their substrate. What does

this mean?

A

The enzyme will only work with particular substrates -those substrates that have the right shape.

64
Q

Which term describes an enzyme in which the active site has permanently changed shape?

A

denatured

65
Q

What effect does a large change of shape of an enzyme’s active site have on how the enzyme works?

A

The enzyme no longer works.

66
Q

Give two examples of changes in the cell environment that could cause the active site to change shape.

A

pH, temperature

67
Q

Carbon dioxide is produced inside a cell and moves out of the cell by diffusion. What does this mean?

A

there is an overall movement of gas particles from

where there are more of them to where there are fewer

68
Q

Name two substances that plants take in from the soil through their roots

A

water and dissolved mineral salts

69
Q

There is a 5% sucrose solution and a 10% sucrose solution. Which solution has the higher concentration of sucrose?

A

10% solution

70
Q

Two beakers contain the same volume of solution. One is a 10% sodium chloride solution, the other is a 5% sodium chloride solution. Which beaker contains more water molecules?

A

5% solution

71
Q

Which solution is used to test for starch and what is the positive result?

A

Iodine solution turns from brown to blue/black

72
Q

Which solution is used to test for protein and what is the positive result?

A

Biurets solution turns from blue to purple

73
Q

What solution is used to test for reducing sugars and what is the positive result?

A

Benedicts solution, once heated, turns from blue to green/orange/red

74
Q

What solution is used to test for lipids and what is the positive result?

A

Ethanol turns from clear to cloudy.