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Biology AS > TOPIC 1A-BIOLOGICAL MOLECULES > Flashcards

TOPIC 1A-BIOLOGICAL MOLECULES Flashcards

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1
Q

A) What are most carbohydrates ( as well as proteins + nucleic acids)?

A

A)-polymers

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2
Q

B) Define “polymers”
C) What are “monomers”?
D) Outline examples of monomers

A

B)-large, complex molecules composed of long chains of monomers joined together
C)-small basic/ molecular units
D)-include monosaccharides/amino acids + nucleotides.

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3
Q

A) Outline the elements do all carbohydrates contain?

B) What monomers are carbohydrates made from and outline some examples

A

A)-C, H and O

B)-monosaccharides like glucose/fructose + galactose.

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4
Q

A) What type of molecule is glucose?

B) Outline the 2 types of glucose molecules and state how they are “isomers”

A

A)-hexose sugar–>monosaccharide with 6 C atoms in each molecule.
B)-alpha (a) glucose/ beta (b) glucose
–>isomers as are molecules with same molecular formula BUT atoms connected in a different way

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5
Q

A) State the formula for a-glucose

A

A) C1:H/OH/C2/C3

  • C2: CH2OH/H/O/C1
  • C3: OH/H/C1/C4
  • C4: H/OH/C5/C3
  • C5: O/C4/H/OH
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6
Q

B) What is the formula for b-glucose?

A 
B)C1:H/OH/C2/C3
-C2: CH2OH/H/O/C1
-C3: OH/H/C1/C4
-C4: H/OH/C5/C3
-C5: O/C4/H/OH
(BUT OH and H groups reversed on C5).
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7
Q

A) Outline what a “condensation reaction” is

B) Describe what happens when monosaccharides are joined via condensation reactions

C) When does a disaccharide form?

A

A)-when 2 molecules join with the formation of new chemical bond + water molecule released when bond formed
B)-glycosidic bond forms between the 2 monosaccharides as a molecule if water released
C)-when 2 monosaccharides join together

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8
Q

D) EXAMPLE: What happens when 2 a-glucose molecules join?

A

D)-they join to form a maltose and a glycosidic bond forms between the 2 a-glucose molecules and also a water molecule is released.

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9
Q

E) How does SUCROSE and LACTOSE form?

A

E)-SUCROSE:-is a disaccharide formed from condensation reaction between glucose molecule + fructose molecule
-LACTOSE-another disaccharide formed from glucose molecule + galactose molecule.

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10
Q

A) Define a “hydrolysis reaction”

B) How may polymers be broken down?

A

A)-breaks chemical bond between monomers using a water molecule–> basically opposite condensation reaction
B)-may be broken down in to monomers via hydrolysis reactions
–> E.G: carbohydrates may be broken down in to their constituent monosaccharides via hydrolysis reactions.

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11
Q

A) Define the term “sugars”

B) Under which 2 categories may sugars be classed under?

C) Which test may be used to test for the presence of “sugars”?

A

A)-general term for monosaccharides + disaccharides
B)-reducing/non-reducing
C)-Benedicts test–> it differs depending on type of sugar testing for.

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12
Q

A)What are “reducing sugars”?

B) Describe the method you would use to carry out the Benedict’s test for “reducing sugars”

A

A)-include all monosaccharides (e.g: glucose) + some disaccharides (e.g: maltose + lactose)
B)1-add Benedict’s reagent (blue) to sample + heat it in water bath that been brought to boil
2-if tests (+)–> coloured precipitate formed (solid particles suspended in solution)
–>colour change: blue–>green–>yellow–>orange–> brick red
3-higher conc of reducing sugar–> further colour change goes–>can use this to compare amount of reducing sugar in different solutions
–>more accurate way to do this–>filter solution and weigh precipitate.

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13
Q

A) When would you use the Benedict’s test to test for the presence of “non-reducing sugars”?

A

A)-if results of reducing sugar test negative–>non-reducing sugar may still be present
–>to test for non-reducing sugars like sucrose first need to break them down in to monosaccharides

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14
Q

B) Outline the method you would use to test for the presence of non-reducing sugars in a sample

A

B)-get new sample of test solution and add dilute HCL

  • ->then carefully heat in water bath that been brought to boil
  • ->then neutralise it with sodium hydrogencarbonate
  • ->then carry Benedict’s test out as normal.
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15
Q

C) What results should you expect from the non-reducing Benedict’s test?

A

C)-if test (+) coloured precipitate forms (same as reducing sugar test)
–> If test (-) solution will stay blue–>meaning that it doesn’t contain any sugar (reducing OR non-reducing).

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16
Q

A) How is a polysaccharide formed?

B) EXAMPLE: Outline the formation of amylose

A

A)-when 2+ monosaccharides joined via condensation reactions

B)-lots a-glucose molecules joined via glycosidic bonds forms amylose

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17
Q

A) Where do cells get energy from?

B) How do plants store excess glucose and how do they obtain energy from it?

C) From which 2 alpha-glucose polysaccharides is starch a mixture of?

A

A)-from glucose
B)-store it as starch
–> when plants need more glucose for energy–> it breaks starch down to release glucose.
C)-amylose and amylopectin.

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18
Q

A) Describe AMYLOSE and how it’s adapted for it’s function

A

A)-long + unbrached chain of a-glucose

  • ->glycosidic bond angles give it a coiled cylinder type of structure
  • -> makes it compact so really good for storage as can fit more in small space.
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19
Q

B) Outline the structure of AMYLOPECTIN and describe its adaptations for it’s function

A

B)-long + branched chain of a-glucose

  • -> it’s side branches allow enzymes that break down the molecule to easily get to the glycosidic bonds
  • -> means glucose quickly released.
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20
Q

C) Why is STARCH good for storage?

A

C)-insoluble in water so doesn’t affect water potential

  • -> therefore doesn’t cause water to enter cells via osmosis–> which would make them swell
  • ->so good for storage.
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21
Q

A) Describe the test you would carry out to test for the presence of starch in a sample

A

A)-add iodine dissolved in potassium iodide solution to test sample
–> if starch present sample colour will change from browny-orange to dark blue-black colour.

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22
Q

A) Where do animal cells get their energy from?

B) How is glucose stored in animals?

A

A)-from glucose too

B)-store excess glucose as glycogen–> another polysaccharide of alpha-glucose.

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23
Q

C) In detail describe the structure of GLYCOGEN

A

C)-structure v. similar to aylopectin except lots more side branches coming off it

  • -> loads of branches means stored glucose can be released quickly which important for energy release in animals
  • -> also v. compact molecule–> so good for storage.
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24
Q

A) What is CELLULOSE?

B) Describe the structure of cellulose

A

A)-major component of cell walls in plants
B)-cellulose made of long + unbranched b-glucose
–> when b-glucose molecules bond–>straight cellulose chains form
–>cellulose chains linked via hydrogen bonds to form strong microfibrils–> strong fibres mean cellulose provides structural support for cells (e.g: in plant cell wall).

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25
Q

A) Outline the composition of TRIGLYCERIDES and what it is

B) Describe the structure of FATTY ACIDS and how it’s suited to it’s function

A

A)-a type of lipid
-composed of one molecule of glycerol + 3 fatty acids attached to it
B)-long “tails” made of hydrocarbons–> these tails hydrophobic (repel water molecules)
–> these tails make lipids insoluble in water
–>all fatty acids have same basic structure but hydrocarbon tail varies.

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26
Q

C) What is the basic structure of fatty acids?

A

C)-C1–>double bond O

  • C1–> OH
  • C1–> R (variable “R” group hydrocarbon tail)
  • carbon atom links fatty acid to glycerol
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27
Q

A) How is a triglyceride formed?

A

A)-fatty acid molecule joins to a glycerol molecule

  • ->this forms an ester bond which also leads to a water molecule being released (condensation reaction)
  • ->this process occurs twice more to form the triglyceride molecule.
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28
Q

A) Outline and describe the 2 types of fatty acids

B) What causes the difference between the 2 types of fatty acids?

A

A)-saturated + unsaturated are the 2 types
-saturated fatty acids–> not have any double bonds between C atoms–>fatty acid saturated with hydrogen
-unsaturated–> fatty acids have at least one double bond between C atoms–>causes chain to kink
B)-difference is in their hydrocarbon tails (R group).

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29
Q

A) What type of lipid is found in cell membranes?

B) State the structure of phospholipids

A

A)-phospholipids found here not tryglycerides
B)-pretty similar to tryglycerides except one of fatty acid molecules replaced by phosphate group
–>phosphate group hydrohphilic (attracts water)
–>fatty acid tails hydrophobic (repel water)
–>this important in cell membranes.

30
Q

Tryglycerides are mainly used as energy storage molecules:

A) How do the “long hydrocarbon tails” of the fatty acids make make tryglycerides adapted to their function?

B) Also, being “insoluble” how does this adaptation of tryglycerides make them suited to their function?

A

A)-they contain lots of chemical energy–> lots of this energy is released when they’re broken down
–>due to these tails–>lipids contain twice as much energy per gram as carbohydrates.
B)-insoluble so don’t affect water potential of cell and cause water to enter cell via osmosis (which would make them swell)
–>tryglycerides clump together as insoluble droplets in cells as the fatty acids are hydrophobic (water-repelling)–>tail faces inwards which shields themselves from water with their glycerol heads.

31
Q

A) What is the function of phospholipids?

B) Outline how the “head” and “tail” of phospholipid molecules make them adapted to their molecule?

C) Why is the “centre” of phospholipids adapted to it’s function?

A

A)-make up bilayer of cell membranes
–>cell membranes control what enters + leaves a cell
B)-heads hydrophilic + tails hydrophobic–>form double layer with their heads facing out towards water on either side
C)-centre of bilayer hydrophobic–>so water soluble substances unable to easily pass through it
–>membrane acts as barrier to those substances.

32
Q

A) What is the “emulsion” test used for?

B) Describe how you would carry out the “emulsion” test

A

A)-used to find out if “fat” present in any particular food
B)1-shake test substance with ethanol for 1 min to dissolve it–>then pour solution in to water
2-any lipid will show up as milky emulsion
3-the more lipid there is–>more noticeable the milky colour will be.

33
Q

A) State the monomers of proteins

B) How is a DIPEPTIDE and POLYPEPTIDE formed?

C) What are proteins made up of?

A

A)-amino acids
B)-dipeptide–>when 2 amino acids join together
-polypeptide–>when more than 2 amino acids join together
C)-made up of one or more polypeptides.

34
Q

A) Outline the same general structure of amino acids

B) EXAMPLE: What is the structure of Alanine?

A

A)-a carboxyl group (-COOH) + amine/ amino group (-NH2) + R group (also known a variable side group)
B)-C1: CH3/COOH/NH2/H

35
Q

C) How many amino acids do all living things share?

D) What is the difference between these amino acids?

A

C)-20 amino acids

D)-only difference is what makes up the R group.

36
Q

A) Explain how polypeptides are formed

B) What type of reaction occurs during digestion?

A

A)-formed when amino acids are joined via condensation reactions
–>water molecule released during reaction
–>peptide bonds formed between amino acids
B)-the reverse reaction

37
Q

A) How are PROTEINS described?

B) Describe the “PRIMARY” structure of proteins

A

A)-big complicated molecules–>easier described as 4 levels
–>primary/secondary/tertiary + quaternary structures.
B)-this is sequence of amino acids in the polypeptide chain

38
Q

C) Outline and explain the “SECONDARY” structure of proteins

A

C)-polypeptide chain not remain flat + straight

  • ->hydrogen bonds form between amino acids in chain
  • ->makes it automatically coil in to alpha (a) helix OR fold in to beta (b) pleated sheets
39
Q

D) In full detail explain the “TERTIARY” structure of proteins

A

D)-coiled or folded chain of amino acid coiled/folded further

  • ->more bonds form between different parts of polypeptide chain including hydrogen/ionic bonds (attraction between - and + charges on different parts of molecule)
  • ->also disulfide bridges form when 2 molecules of amino acid cysteine come close–>sulfur atom in one cysteine bonds to sulfur atom in other
  • for proteins made from single polypeptide chain tertiary structure forms final 3D structure.
40
Q

E) Describe and explain the “QUATERNARY” structure of proteins

A

E)-some proteins made from several different polypeptide chains held together via bonds

  • ->quaternary structure is way these polypeptide chains assembled together
  • for proteins made from 2+ polypeptide chains (e.g: haemoglobin/insulin/collagen) quaternary structure is protein’s final 3D structure.
41
Q

For each of the following enzymes found in living organisms outline their shape and structure and how that consequently makes them specialised to carry out their particular job:

A) ENZYMES

A

A)-usually spherical shape due to tight polypeptide chain folding
–>they are soluble + often have roles in metabolism (e.g: some break down large food molecules-digestive enzymes AND others help synthesise (make) larger molecules.

42
Q

B) ANTIBODIES

A

B)-involved in immune response–> made of 2 light (short) polypeptide chains + 2 heavy (long) polypeptide chains bonded together
–>antibodies have variable regions–>amino acid sequences in these regions vary greatly.

43
Q

C) TRANSPORT PROTEINS

A

C)-e.g: channel proteins present in all

  • channel proteins contain hydrophobic (water hating) + hydrophilic (water loving) amino acids which cause protein to fold up on and form channel
  • ->these proteins transport molecules + ions across membranes.
44
Q

D) STRUCTURAL PROTEINS

A

D)-are physically strong

  • consist of long polypeptide chains lying parallel to each other with cross-links between them
  • structural proteins include keratin (found in hair + nails) + collagen (found in connective tissue).
45
Q

A) What test is used to test for the presence of protein in a sample of something?

B) Describe how you would carry out this test

A

A)-Biuret test used
B)1-test solution needs to be alkaline–>so first add few drops of sodium hydroxide solution
2-add some copper (II) sulfate solution
–>if protein present solution turns purple
–>if no protein solution stays blue
(need to look carefully as colours are pale).

46
Q

A) What are enzymes and what is their function?

B) How may enzymes affect structures and functions in organisms?

A

A)-are proteins
-catalyse metabolic reactions–>both at cellular level (e.g: respiration) AND for organisms as whole (e.g: digestion in mammals)
B)-e.g: enzymes involved in production of collagen–> important protein in animal’s connective tissues
-can affect functions like respiration

47
Q

C) Where may enzyme action take place?

D) Briefly explain why an enzyme’s structures make them specific

E) What makes enzymes highly specific?

A

C)-intracellular–>within cells OR extracellular–> outside cells
D)-have active site which has specific shape
–>active site is part of enzyme where substrate molecules (substance enzymes interact with) bind to
E)-are highly specific due to their tertiary structure.

48
Q

A) Define the term “ACTIVATION ENERGY”

B) What is the effect of enzymes on the activation energy of a reaction?

A

A)-in chemical reaction certain amount of energy needs to be supplied to chemicals before reaction will start
–>often provided as heat
B)-lower amount of activation energy needed–>often making reactions happen at lower temp than could without enezyme
–>speeds up chemical reaction

49
Q

C) How does an “enzyme-substrate complex” form?

D) Explain the 2 ways as to how the formation of an “enzyme-substrate complex” lowers the activation energy of a reaction

A

C)-when substrate fits in to enzyme’s active site
D)1-if 2 substrate molecules need to be joined–>being attached to enzyme holds them closer together–> reducing repulsion between molecules so can bond easier
2-if enzyme catalysing a breakdown reaction–> fitting into active site puts strain on bonds in substrate so substrate molecule breaks up more easily.

50
Q

A) Describe the “lock and key” model to describe enzyme activity

A

A)-enzymes picky–>only work with substrates that fit in their active site
-early scientists came up with this model where substrate fits into enzyme same way key fits in to lock.

51
Q

B) Explain what scientists soon realised about the “lock and key” model for enzyme activity and what that then consequently meant

A

B)-it didn’t give full story

  • enzyme + substrate have to fit together in first place but new evidence showed enzyme-substrate complex changed shape slightly to complete fit
  • ->this locks substrate tighter to enzyme so scientists modified lock + key model to come up with “induced fir” model.
52
Q

A) What does the “induced fit model” help to explain?

B) Describe the induced fit model

C) Outline what this change in the enzyme model is a prime example of

A

A)-helps to explain why enzymes are so specific and only bond to one particular substrate
B)-substrate not only have to be right shape to fit active site–>has to make active site change shape in right way too
C)-prime example of how a widely accepted theory can change when new evidence comes along
–>induced fit model accepted for now-may change.

53
Q

A) Explain how the specificity of enzyme’s active sites are determined by their tertiary structure

A

A)-enzymes specific as only catalyse one reaction normally (e.g: maltase only breaks maltose down/sucrase–>sucrose)

  • ->this a one complementary substrate will fit into active site
  • ->active site’s shape determined by enzyme’s tertiary structure (which determined by enzymes primary structure).
54
Q

B) Explain how the tertiary structure of an enzyme affects it

A

B)-enzyme has different tertiary structure and so different shaped active site
–> if substrate shape not match active site–>enzyme substrate complex wont form and reaction not catalysed.

55
Q

C) What would happen if the tertiary structure of an enzyme is altered in any way?

D) How may the tertiary structure of an enzyme be altered?

E) Briefly explain how change to the primary structure of an enzyme could lead to change to the tertiary structure of an enzyme

A

C)-active site shape would change
–>means substrate no longer fit in to active site–>enzyme substrate complex won’t be formed and enzyme no longer functional
D)-via changes in pH or temperature
E)-primary structure (amino acid sequence) of protein determined by a gene
–>if there is a mutation occurs in the gene–>could change tertiary structure of enzyme produced.

56
Q

A) Explain what happens to the rate of an enzyme-controlled reaction (chemical reaction) when the TEMPERATURE is continuously increased

A

A)-increases–>more heat means K.E increases so molecules move faster

  • ->makes enzyme collision more likely with substrate molecules
  • ->energy of these collisions also increases–>means each collision more likely to result in reaction
  • ->BUT if temp eventually too high reaction stops.
57
Q

B) Outline and describe what happens to the structure of enzymes as the temperature is increased

A

B)1-temp rise makes enzyme molecules vibrate more
2-if temp goes above certain level–>this vibration breaks some of bonds holding enzyme in shape
3-active site shape changes and enzyme substrate no longer fit together
4-at this point enzyme denatured–>no longer functions as catalyst.

58
Q

A) What term is given to all enzymes pH value?

B) Outline the pH value most humans enzymes work at

C) State and briefly explain an enzyme example which is an exception to the rule

A

A)-optimum pH value
B)-pH 7 (neutral)
C)-pepsin–>works best at pH 2 which useful as found in stomach

59
Q

D) Explain how above or below the optimum pH of an enzyme can lead it to becoming denatured

A

D)-the H+ and OH- ions found in acids and alkalis can mess up ionic bonds + hydrogen bonds that hold enzyme’s tertiary structure in place

  • ->makes active site shape change
  • ->DENATURED.
60
Q

A) In appropriate detail explain how enzyme concentration affects the rate of a reaction

B) What would happen if the amount of substrate is limited?

A

A)-more enzyme molecules in solution–>more likely substrate molecule will collide with one and form enzyme-substrate complex
–>so increasing enzyme conc increases reaction rate
B)-come to point where more than enough enzyme molecules to deal with all available substrate so adding more enzyme has no further effect.

61
Q

A) Why would the rate of reaction stop increasing after a certain point if the substrate concentration is continually increased?

A

A)-initially higher substrate con–>faster reaction as more substrate molecules means collisions between substrate + enzyme more likely so more active sites will be used

  • ->this only true up to “saturation” point
  • ->after that so many substrate molecules that enzymes cant cope with more (all active sites full) so adding more substrate makes no difference.
62
Q

B) Explain why the initial rate of reaction is the highest in terms of substrate concentration

A

B)-substrate conc decreases over time (unless more substrate added to reaction mixture)

  • ->so if no other variables changed–>reaction rate will decrease over time
  • ->so this makes initial reaction rate highest.
63
Q

A) What are “enzyme inhibitors” and under which 2 forms can this inhibition take place?

A

A)-they prevent enzyme activity–>molecules that bind to enzyme that they inhibit
-inhibition can be competitive OR non-competitive.

64
Q

B) Explain how COMPETITIVE INHIBITION works

A

B)-competitive inhibitor molecules have similar shape to that of the substrate molecules

  • ->they compete with substrate molecules to bind to active site BUT no reaction takes place
  • ->instead they block active site–>so no substrate molecule can fit in it.
65
Q

C) How does the concentration of inhibitors and substrate affect enzyme inhibition?

A

C)-if there’s high conc of inhibitor–>will take up nearly all active sites and hardly any of substrate will get to enzyme

  • ->but if higher conc of substrate then substrate’s chances of getting to an active site before inhibitor increases
  • ->so increasing conc of substrate will increase reaction rate up to a point.
66
Q

A) Describe how NON-COMPETITIVE INHIBITORS work

B) Outline the effect of increasing the concentration of substrate on enzyme activity during non-competitive inhibition

A

A)-non-competitive inhibitor molecules bind to enzyme away from it’s active site
–>causes active site shape to change so substrate molecules no longer able to bind to it
–>they don’t compete with substrate molecules to bind to active site as are different shape
B)-wont make any difference to reaction rate–> enzyme activity will still be inhibited.

67
Q

A) Outline how you would measure the rate of an enzyme-controlled reaction through measuring how fast the product of the reaction is made using catalase

B) What apparatus would be used to measure the rate of reaction?

A

A)-catalase catalyses breakdown of hydrogen peroxide to water + oxygen
–>easy to measure oxygen volume produced + how fast its given off
B)-oxygen released displaces water from measuring cylinder
-stand + clamp stand (be useful to hold cylinder upside down) + stopwatch + waterbath.

68
Q

C) How would you carry out this experiment?

show the full method

A

C)1-set boiling tubes up with same volume + conc of hydrogen peroxide
–>to keep pH constant add equal volumes of suitable buffer solution to each test tube (resists pH change)
2-set up apparatus shown in diagram
3-put each boiling tube in water bath set at different temperatures (e.g: 10/20/30/40 degrees C) WITH tube containing catalase (wait 5 min before next step so enzyme can reach required temp)
4-pipette–>add same volume + conc of catalase to each boiling tube–>then quickly attach bung + delivery tube
5-record oxygen volume produced in 60 so of reaction
–>use stopwatch to measure time
6-repeat at each temp x3–> then find avergae O2 volume produced
7-calculate average reaction rate at each temp by dividing O2 volume produced by time taken–>units will be cm3s-1.

69
Q

A) How would you measure the rate of an enzyme controlled reaction through measuring how fast the substrate is broken down? Include the following:

  • equipment
  • method
A

A)-enzyme amylase catalyses breakdown of starch to maltose
-equipment–>will need apparatus shown in diagram + stopwatch
-method–>1-iodine in potassium iodide drop in each well on spotting tile
2-known conc of amylase + starch mixed in test tube
3-dropping pipette used to put drop of this mixture into one of the wells containing iodine solution on spotting tile at regular intervals–>resulting colour observed.
4-iodine solution goes dark blue-black when starch present BUT remains normal browny-orange when no starch around
5-can see how fast amylase working by recording how long takes for iodine solution no longer colour blue/black when starch or amylase mixture added
6-repeat experiment using different conc of amylase–> repeat experiment x3 at each amylase concentration.

70
Q

The experiments previously described shows how you can investigate effect of temp + enzyme conc on rate of enzyme controlled reactions. Outline how altering the experiment in the following ways could also be used to investigate effect of different variables on the rate of the reaction:

A) pH
B) Substrate concentration

A

A)-by adding buffer solution with different pH to each test tube
B)-could use serial dilutions to make up substrate solutions with different concentrations
-key to experiments like this is to remember to only change 1 variable–>everything else should remain same.

71
Q

Results of an enzyme-controlled reaction could be shown in a line graph and you could be asked to interpret it. The following graph shows the release of product over time. Interpret the graph:

A) What would you say about the start of the graph?

B) Now look at the rest of the graph and outline what you see

A

A)-compare the rates here–>E.G: rate of reaction fastest at 65 degrees C
-use knowledge on factors affecting enzyme activity to explain why
–>may have to work out initial reaction rate.
B)-make comparisons between different temperatures
-at 37 degrees C: graph has plateaued (flattened) as all substrate used up
-at 65 degrees C: graph plateaued earlier than 37 degrees C as high temp caused enzyme to denature so reaction stopped sooner
–>not as much product made as not all substrate converted to product before enzyme denatured so substrate still left
-at 25 degrees C: reaction rate is remaining constant + volume of product continuing to increase as not all substrate used up

72
Q

A) What is the initial rate of reaction of a reaction?

B) Outline how you would work out the initial rate of reaction from a graph

A

A)-is rate of reaction at start of a reaction close to t=0 on graph
B)1-draw tangent to curve at t=0 using ruler
–>do this by positioning ruler so its equal distance from curve at both sides of where it’s touching
–>here will have to estimate where curve would continue if carried on below 0–>then draw line along ruler
2-then calculate gradient of tangent–>this is initial rate of reaction
–>gradient=change in y/change in x.
–>in this case it would be 40cm3/8s=5cm3s-1

Biology AS (6 decks)

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