Brainscape's Knowledge GenomeTM

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


See full index

Biology Y9 > Biological Molecules > Flashcards

Biological Molecules Flashcards

1
Q

chemical elements in carbohydrates

A

carbon oxygen and hydrogen

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

chemical elements in protein

A

carbon oxygen hydrogen and nitrogen (some contain sulphur)

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

monosaccharide and examples

A

-a simple sugar (simplest)
-glucose or fructose

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

disaccharide and examples

A

-made when two monosaccharides join together
-maltose (2 glucose molecules)

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

polysaccharide and examples

A

-forms when lots of monosaccharides join together
-starch, glycogen and cellulose
-insoluble, useful as storage molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are lipids made out of

A

most are:
-triglyceride, formed from one glycerol molecules chemically bonded to three fatty acids (acidic when broken up due to fatty acid)
-they are divided into two groups : fats (solid at room temp) and oils (liquid at room temp)

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

what are proteins formed from, and examples of proteins

A

-long chains of amino acids join together to form a protein
-differently arranged amino acids can form different proteins
-different proteins thus have different shapes, and the shape determines its function
-e.g. enzymes, haemoglobin, ligaments and keratin

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

steps to prepare a food sample

A
  1. break up the food using a pestle and mortar
  2. transfer to a test tube and add distilled water
  3. mix the food with water by stirring with a glass rod
  4. filter the mixture using a funnel and filter paper, collecting the solution (filtrate)
  5. proceed with the food tests
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

test for glucose

A
  1. add benedict’s solution to the sample solution in a test tube
  2. Heat in a boiling water bath for 5 minutes
    3, take the test tube out and observe the colour
  3. positive test changes solution from blue to green, yellow, orange and brick-red from low to high concentration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

safety precautions for glucose test

A

-handle test tube with tongs
-wear safety googles, heatproof gloves

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

test for starch

A
  1. add food sample to a test tube
  2. add a few drops of iodine solution
  3. positive test shows colour change from orange-brown to blue-black
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

hazards in test for starch

A

-iodine is an irritant to the eyes, wear googles
-sodium hydroxide is in biuret solution, which is corrosive, wash skin if it touches your skin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

protein food test

A
  1. add drops of biuret solution to the food sample
  2. positive test goes from blue to violet/purple
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

hazards in test for protein

A

biuret solution contains copper 2 sulfate which is dangerous if it gets in the eyes, wear googles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

test for lipids (fats)

A
  1. mix the food sample with 4 (or 2)cm of ethanol and shake
  2. allow time for the sample to dissolve in the ethanol
  3. strain the ethanol solution into another test tube
  4. add the ethanol solution to an equal volume of cold distilled water 4 (or 2)cm
  5. a positive test will show a cloudy emulsion forming, colourless in negative test result
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

hazards in test for lipids

A

-ethanol is highly flammable, keep it away from bunsen burners

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

why is ethanol used in test for lipids

A

fats and oils are insoluble in water but will dissolve in ethanol

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

what are enzymes

A

-proteins that acts as biological catalysts to speed up the rate of a chemical reaction without being changed or used up in the reaction

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

why are enzymes biological

A

they are made in living cells

20
Q

why are enzymes necessary

A

they main reaction speeds of all metabolic reactions at a rate that can sustain life

21
Q

metabolic reaction

A

all of the reactions in an organism or a cell that keep it alive

22
Q

why are enzymes specific to one particular substrate

A

the active site of the enzyme is a complementary shape to the substrate

23
Q

active site

A

where the substrate attaches to

24
Q

enzyme substrate complex meaning

A

when the substrate moves into the enzyme’s active site

25
Q

steps for a reaction to be catalysed

A
  1. enzymes and substrate randomly move about in solution
  2. when an enzyme and its complementary substrate randomly collide and enzyme substrate complex forms and the reaction occurs
  3. a product forms from the substrates which are then released from the active site
  4. enzyme is unchanged and will go catalyse more reactions
26
Q

optimum temperature in the human body

A

37 degrees celcius

27
Q

denaturation

A

-heating to high temperatures breaks the bonds that hold the enzyme together and it will lose its shape
-substrates cannot fit into denatured enzymes as the shape of their active site has been lost
-enzymes cannot regain their proper shape and activity will sop

28
Q

effect of temperature on enzyme activity

A
  1. increasing the temperature towards the optimum increases the activity of enzymes.
  2. Because as more temperature is proportional to kinetic energy, so the molecules move faster and the number of collisions with the substrate molecule increases. leading to a faster rate of reaction
  3. when the temperature is above the optimum, the rate of enzyme activity decreases sharply
  4. because the active site is being deformed as the bonds that hold the enzymes are being broken, changing its shape. The denatured enzyme can longer catalyse reactions and the rate of enzyme activity decreases

MS for denature
1. denatured
2. active site
3. no longer fit/bind/changes shape/deformed

29
Q

effect of pH on enzyme activity

A

-if the pH is too high or low compared to the pH, the bonds that hold the amino acid chain to make the protein can be disrupted or destroyed
-this changes the shape of the active site, so the substrate can no longer fit into it, reducing rate of activity
-moving too far from the optimum pH will cause enzyme to denature

(amino acids carry charges, and are attracted to each other. different pH can affect the charges and cause the amino acid to no longer be attracted, changing the shape of the active site

30
Q

diffusion definition

A

movement of molecules from a region of higher concentration to a region of lower concentration

31
Q

how do particles diffuse

A

through the random movement of molecules resulting in the molecules spreading out until there is an even concentration throughout the space

32
Q

how do molecules move into and out of living cells

A

-diffusion through the partially permeable cell membrane
-smaller molecules can diffuse across the cell membrane but larger ones cannot as it is partially permeable

33
Q

what does diffusion allow living organisms to do

A

-gain nutrients in the digestive system
-gain oxygen in the lungs
-remove waste products in the lungs and kidneys

34
Q

osmosis

A

the movement of water molecules from a region of higher water potential to a region of lower water potential

35
Q

effect of osmosis on animal cells(no cell wall) in higher and lower water concentrations

A

-in low water concentration: the cell loses water, becoming crenated/shrivelled
-in high water concentration, the cell gains water, eventually bursting as it lacks a cell wall to maintain structure

36
Q

effect of osmosis on plants cells(cell wall) in higher and lower water concentrations

A

-low water concentration, cell loses water, the vacuole shrinks and the cell membrane pulls away from the wall, making the cell flaccid
-high water concentration, cell gains water, vacuole expands and the membrane pushes against the cell wall, making the cell turgid

37
Q

why is energy needed in active transport

A

-the particles are being moved against a concentration gradient

38
Q

active transport

A

the movement of particles across a cell membrane from a region of lower concentration to a region of higher concentration using energy

39
Q

what molecules are involved in active transport

A

protein carrier molecules embedded in the cell membrane

40
Q

examples where active transport is used

A

-absorption of products of digestion into bloodstream from the lumen of small intestine
-absorption of mineral ions from the soil into the root hair cells of plants

41
Q

factors affecting diffusion

A

-surface area to volume ratio
-diffusion distance
-temperature
-concentration gradient

42
Q

how does SA:V affect rate of diffusion

A

-the bigger a cell is, the smaller its SA:V ratio is, slowing down rate of diffusion
-because the area in which substances can move across its surface is less

43
Q

how does diffusion distance affect rate of diffusion

A

-the smaller the distance molecules have to travel the faster transport will occur

44
Q

how does temperature affect rate of diffusion

A

the higher the temperature, the faster molecules move as they have more kinetic energy, which is proportional to temperature

45
Q

how does concentration gradient affect rate of diffusion

A

the greater the difference in concentration on either side of the membrane, the faster movement across it will occur

46
Q
A

Biology Y9 (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions