Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

bio > biological molecules > Flashcards

biological molecules Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

what do carbohydrates, proteins and lipids contain, give examples of each

A

carbohydrates: CHO carbon, hydrogen, oxygen
eg. glucose, glycogen, starch, cellulose

proteins: CHON (S) carbon, hydrogen, oxygen, nitrogen, sometimes sulphur
eg. enzymes, hormones, blood proteins

lipids: CHO carbon, hydrogen, oxygen
eg. fats, oils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what determines how the proteins function

A

the different amino acids and their structure can determine the shape, size, properties of the protein and how it folds in different ways

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

protein food test

A

biuret test
neg- blue
pos- purple

  1. half fill test tube with extract you wish to test
  2. add 5-6 drops of biuret solution (contains copper sulfate solution and sodium hydroxide solution)
    Safety: sodium hydroxide is corrosive
  3. if color remains blue: no protein; if color turns purple: contains protein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

lipids food test

A

ethanol emulsion test
fats will not dissolve in water but will dissolve in ethanol, if a solution of fat in ethanol is added to water, a cloudy white emulsion is formed

  1. grind/chop a small amount of the material you wish to test
  2. put the extract into a test tube and add enough ethanol to cover it
  3. put a stopper on the test tube and shake the contents
  4. add distilled water until the test tube is half full, then repeat 3
  5. if cloudy white emulsion formed- contains fat: does not happen, does not contain fat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

starch food test

A

iodine test

  1. half fill a test tube with food extract then add 2-3 drops of iodine solution
  2. positive: blue-black, contains starch ; negative: remains yellow/light brown
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

reducing sugars test

A

Benedict’s test

  1. place the sample in a test tube
  2. set up a hot water bath: beaker on heat proof mat, half-fill a beaker with boiling water/ place beaker on tripod and gauze and boil water with Bunsen burner
  3. add the same volume of Benedict’s solution to the test tube containing the food extract, put tube in hot water bath
  4. Positive test: red/orange (look carefully you see it turn green and yellow before orange), if you leave it to cool you will see a precipitate

green: only a little reducing sugar present
deep orange: lots of reducing sugars

negative: blue, does not contain any

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

vitamin C test

A

DCPIP test

DCPIP is a blue liquid that loses its color when it comes into contact with vitamin C

  1. put a known volume of DCPIP solution in a test tube
  2. fill a syringe/dropping pipette with a solution of vitamin C or juice (eg. ogjuice)
  3. add the liquid one drop at a times
  4. if color of DCPIP disappears: test is positive
    if blue color persists then the test is negative

Vit C decolourises DCPIP solutions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

biological molecules are _____ _____ like _____, _____ and _____

they are useful chemicals needed by _____ _____ for _____

by _____ we mean all the _____ _____ taking place in the _____ of the body

these reactions include the release of _____ in _____, _____ _____, and the _____ and _____ of cells

A

biological molecules are complex chemicals like carbohydrates, proteins and fats

they are useful chemicals needed by living organisms for metabolism

by metabolism we mean all the chemical reactions taking place in the cells of the body

these reactions include the release of energy in respiration, protein synthesis, and the growth and repair of cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what do green plants use simple raw materials for?

A

green plants make the complex chemical compounds that they need from simple raw materials
CO2 and H2o are the raw materials for photosynthesis

simple sugars produced in photosynthesis used to make a wide range of other compunds
- plants need minerals to make some of these complex compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

the different biological molecules needed for a balanced diet in humans are what?

A

carbohydrates, proteins, fats, vitamins, minerals, fibre and water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

describe carbohydrates

what is cellulose used for
what is starch used for
what is glycogen used for

A
  • made of many sugar molecules containing CHO atoms
  • glucose is a small sugar molecule
    when many glucose bind together in a chain, cellulose, starch and glycogen can be made

cellulose is used for structure and makes up plant cell walls
starch and glucose are stored in cells and used in respiration to provide energy for the organism

starch is stored in PLANTS
glycogen is stored in ANIMALS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

describe fats/lipids

A
  • made up of glycerol and fatty acids which contain CHO
  • have a variety of roles in organisms: insulation, energy, waterproofing, structure and protection around delicate organs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

describe proteins

A
  • made up of CHON(S), these elements make up amino acids which bind together in a chain to make proteins
  • different arrangements of amino acids make up different proteins and form different shapes
  • enzymes are proteins; each enzyme active site has a specific shape
  • antibodies also have a specific shape, formed by a specific sequence of amino acids
  • this allows them to bind to antigens on foreign pathogens to kill them
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

why is water an important solvent

A
  • its an important molecule which is a major component of cells
  • acts as solvent in which many chemical reactions occur, helps to maintain a constant temperature in the body and is a metabolite
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

why is water needed for digestion

A

needed for digestion to provide a medium for enzymes to act in and to allow free passage of digestive products, so they can be absorbed into the blood
- allows soluble molecules, such as products of digestion to be transported around the body and through cell membranes

transports waste products such as urea and carbon dioxide to be excreted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what smaller molecules are starch and glycogen made from?

A

glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what smaller molecule is cellulose made of

A

glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what smaller molecules are proteins made of

A

amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what smaller molecules are fats and oils made from

A

fatty acids

glycerol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

give 2 functions of proteins

A

antibodies

enzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

describe the structure of DNA

A
  • polymer made of many nucleotide monomers
  • made of 2 strands in the shape of a double helix
  • each strand contains bases (A, T, C, G)
  • 2 strands linked between the bases
22
Q

4 bases of DNA and how they join

A

A with T

C with G

23
Q

give one use of water in the body

A

as a solvent

24
Q

3 processes in which water is used as a solvent

A

digestion, excretion, transport

25
Q

define active site

A

a specific region of an enzyme where the substrate binds and the reaction takes place

26
Q

define amino acids

A

small molecules from which proteins are synthesised

27
Q

define antibodies

A

proteins produced by lymphocytes in response to a specific antigen, triggering an immune response
Antibodies have binding sites complementary to a particular antigen

28
Q

define antigen

A

a unique chemical present on the surface of a cell that induces an immune response

29
Q

define Benedict’s test

A

chemical test used to test for reducing sugars that produces a different colour based on the amount of reducing sugar present

30
Q

define biuret test

A

chemical test that produces purple color in presence of protein

31
Q

define carbohydrate

A

large molecule synthesised from simple sugars

32
Q

define cellulose

A

a type of carbohydrate made from many glucose molecules joined together

main component of cell walls in plants

33
Q

define complementary base pairing

A

describes how cross links form between complementary base pairs
AT Cg

34
Q

define DCPIP test

A

chemical test for vit C

upon addition, color change from blue to colourless indicates positive test

35
Q

define DNA

A

double stranded polymer of nucleotides wound to form a double helix that carries the genetic code

36
Q

define Emulsion test

A

chemical test produced cloudy white emulsion when performed on lipids

37
Q

define fats

A

lipids that are solid at room temp

38
Q

define fatty acids

A

Small molecules from which fats are synthesised (along with glycerol)

A molecule of fat contains 3 fatty acid molecules

39
Q

define glucose

A

A small molecule from which many carbohydrates (eg. glycogen, starch, cellulose) are synthesised

40
Q

define glycerol

A

a component of fat molecules

41
Q

define iodine test

A

chemical test produced blue black color when iodine sol is added to sample containing starch

42
Q

define lipids

A

a group of large molecules that are synthesised from fatty acids and glycerol

43
Q

define nucleotides

A

The monomers of DNA consisting of a 5-carbon sugar, a phosphate group and one of four chemical bases (A,T,C,G) attached to the sugar

44
Q

define oils

A

lipids that are liquid at room temp

45
Q

define protein

A

large molecule synthesised from amino acids

46
Q

define solvent

A

a substance which other solutes are dissolved in eg. water

47
Q

define starch

A

a type of carbohydrate made from many glucose molecules joined together
it serves as an energy store in plants

48
Q

Name the small molecules that are used to make (i) cellulose and (ii) fats.

A

(i) Glucose is the small molecule used to make cellulose.
(ii) Three fatty acids combine with glycerol to make a molecule of fat. Glycogen is a complex compound formed from many glucose molecules.

49
Q

DNA molecules have a double helix structure. Explain what this means.

A

There are two strands that are coiled around each other.

Two strands are held together by weak bonds.

50
Q

(e) State the precise site of DNA in an animal cell.

[2 marks].

A

In the nucleus the DNA makes up the chromosomes in the nucleus

bio (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions