Brainscape's Knowledge GenomeTM

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


See full index

Biology > topic 1 > Flashcards

topic 1 Flashcards

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

monomers

A

small units which are the components of larger molecules

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

polymers

A

molecules made

from many monomers joined together.

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

polysaccharide

A

monosaccharides joined together with a glycosidic bond formed in a condensation reaction.

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

monosaccharide

A

monomer of carbohydrates

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

maltose

A

glucose + glucose

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

sucrose

A

glucose + fructose

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

lactose

A

glucose + galactose

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

starch

A

-stores energy in plants
-when broken down can be used for respiration and cell growth
-formed from alpha glucose
-a mixture of two polysaccharides called amylose and
amylopectin.
-amylose made up of glucose connected by 1-4 glycosidic bonds. helical structure and unbranched.
-amylopectin helical structure with 1-4- glycosidic bonds. has several branches connected by 1-6 glycosidic bonds.
-insoluble so water potential of cell/organelle doesn’t change.
-helical structure is compact so lots of glucose can be stored in less space
-branches provide large SA for faster hydrolysis of starch into alpha glucose so more photosynthesis for the plant to grow.

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

glycogen

A
  • store of glucose in animals
  • found in liver and muscle cells
  • formed from many molecules of alpha glucose
  • helical structure joined by 1-4 glycosidic bonds and has several branches connected by 1-6 glycosidic bonds.
  • -insoluble so water potential of cell/organelle doesn’t change.
  • helical structure is compact so lots of glucose can be stored in less space
  • branches provide large SA for faster hydrolysis of starch into alpha glucose to be used for respiration
  • has more branches than starch because animals have a higher metabolic need
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

cellulose

A

-the main component of cell walls
-composed of beta glucose
-every other beta glucose molecule is inverted in order for the two OH groups to bond and form a glycosidic bond.
-this leads to the formation of long, unbranched, straight and parallel chains.
-chains held together by H bonds form microfibrils which make up cellulose fibres.
-cellulose fibres intertwine in a lattice structure to form cellulose
-Cellulose is important in stopping the cell wall
from bursting under osmotic pressure as it exerts pressure. This means that cells stay turgid and rigid, helping to maximise the surface area of plants for photosynthesis.
-Cellulose has structural strength as there are lots of H bonds between its chains. When cellulose fibres intertwine, the strength increases further.

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

test for reducing sugar

A
  • add benedict’s reagent and heat

- a positive test observation turns from blue to green, yellow, orange or brick red

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

test for non-reducing sugar

A
  • following a negative benedict’s test where the reagent remains blue
  • add acid and boil (to hydrolyse the disaccharide into two monosaccharides by breaking the glycosidic and freeing the reducing group)
  • cool solution (so a vigorous reaction doesn’t occur and the solution doesn’t effervesce)
  • add an alkali to neutralise (so the benedict’s works properly)
  • add benedict’s reagent and heat
  • a positive test observation turns from blue to green, yellow, orange or brick red
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what do colorimeters do

A

-measure the % absorbance of particular wavelengths of light by a specific solution or % light transmitted through the solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

equations for concentration

A 
conc = mass/vol (for solids)
C1V1 = C2V2 (for solutions)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

reasons for conducting serial dilutions

A
  • can make up solutions with very small concs more accurately as small masses or volumes are very hard to measure precisely.
  • larges no.s of microorganisms are difficult to count. the original culture can be diluted using a series dilution method and a smaller number of colonies can be counted. this can then be multiplied up to find the original no. of colonies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

test for starch

A

iodine turns from orange/brown to blue/black

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

which elements are lipids made from

A

carbon, hydrogen and oxygen

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

triglyceride structure

A

one molecule of glycerol and 3 fatty acids joined by ester bonds formed in condensation reactions

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

saturated lipids

A
  • e.g. animal fats

- no C=C

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

unsaturated lipids

A
  • can be found in plants
  • contain C=C
  • molecule is able to bend due to double bond
  • can’t pack together as tightly so are liquid at room temperature
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

how does the structure of triglycerides relate to its function

A
  • high ratio of energy storing carbon-hydrogen bonds compared to carbon atoms so are a good store of energy
  • good storage molecule, with a lot of energy being stored in a small volume. This is beneficial for animals as it is less mass to move around.
  • Being large and non-polar lipids are insoluble in water and therefore their storage does not affect the water potential of cells.
  • triglycerides release water when they are oxidised and therefore provide and important source of water for organisms to live in dry environments.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

phospholipid structure

A
  • one of the fatty acids of a triglyceride, is substituted by phosphate-containing group
  • phosphate heads are hydrophilic and the tails are hydrophobic.
  • they form micelles when in contact with water
  • they are polar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

how does the structure of phospholipids relate to its function

A
  • they are polar so a bilayer can be formed
  • the hydrophilic heads of the phospholipids can be used to hold at the surface of the cell surface membrane
  • their structure allows them to form glycolipids with carbohydrates which are important on the cell surface membrane for cell recognition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

structure of amino acids

A
  • amine group (NH2)
  • carboxylic acid group (COOH)
  • variable R group
  • they join by peptide bonds formed in condensation reactions. a h2o molecule is produced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

how to carry out a serial dilution from 10moldm-3 to 0.1moldm-3

A
  • pour 10cm3 of the 10moldm-3 solution into a test tube.
  • transfer 1cm3 of this solution into another test tube containing 9cm3 of water.
  • mix thoroughly
  • transfer 1cm3 of the diluted solution to another test tube with 9cm3 of water.
  • mix thoroughly
  • this solution has a conc of 0.1moldm-3
26
Q

how to carry an emulsion test

A
  • add 2cm3 of the test sample to a dry test tube
  • add 5cm3 of ethanol and mix the solution thoroughly to dissolve all of the lipid in the solution
  • add 5cm3 of water and mix
  • a white emulsion indicates the presence of a lipid
27
Q

primary structure of proteins

A
  • order and number of amino acids in the polypeptide chain.

- contains the initial sequence of amino acids so will determine the protein’s function

28
Q

secondary structure of proteins

A
  • the folding of the chain of amino acids
  • becomes either alpha helix or beta pleated sheet
  • their shape is maintained by H bonds
29
Q

tertiary structure of proteins

A
  • the 3D shape of the protein and is formed from further twisting and folding.
  • structure maintained by the side chains of amino acids
  • disulfide bridges, ionic bonds and H bonds
30
Q

testing for proteins

A
  • add test solution to test tube (if solid then finely chop, add distilled water and shake)
  • add 10 drops of biuret reagent to the solution
  • a positive test shows colour change from blue to purple due to the presence of peptide bonds
31
Q

what are enzymes

A

-enzymes increase rate of reaction by lowering the activation energy of the reaction they catalyse. They are 3D tertiary structured globular proteins whose shape is determined by the primary sequence of amino acids.

32
Q

how do enzymes and substrates fit together

A
  • the active site on an enzyme is specific and unique in shape due to the specific folding and bonding in the tertiary structure of the protein.
  • therefore, enzymes can only attach to substrates that are complementary in shape
33
Q

describe the lock and key model

A
  • suggests enzyme is like a lock and substrate is like a key that fits in due to the complementarity in shape
  • enzyme active site shape is fixed
  • due to random collisions, the substrate can collide and attach to the enzyme, forming an enzyme-substrate complex
  • the charged groups within the active site distort the substrate and therefore lower the activation energy
  • the products are released and the enzyme active site is empty and ready to be reused
34
Q

describe the induced fit model

A
  • the enzyme active site slightly changes shape to mould around the substrate
  • when the enzyme-substrate complex forms due to the moulding of the enzyme around the substrate, it puts strain on the bonds and therefore lowers activation energy
  • the products are then removed and the enzyme active site returns to its original shape
35
Q

how do enzymes help to speed up rates of reaction

A
  • when enzymes attach to the substrate, they can lower the activation energy needed for the reaction to occur.
  • they assist in the making or breaking of bonds
36
Q

explain the relationship between temperature and RoR

A
  • as temp increases there is an increase in KE so molecules move faster leading to more successful collisions between enzyme active site and substrate
  • when the temp is too high and there is too much KE, H bonds, ionic bonds and disulfide bridges break so the active site changes shape.
  • therefore the active site is no longer complementary in shape to the substrate so fewer enzyme-substrate complexes form
  • eventually, the enzyme becomes denatured and loses its catalytic properties
37
Q

explain the relationship between pH and RoR

A
  • enzymes have an optimum pH at which they work fastest
  • if the pH is too high, the H bonds or ionic interactions of the 3D enzymes may be broken by the high concentration of H+ ions present
  • the active site will change shape and no longer be complementary in shape to the substrate
38
Q

explain the relationship between substrate concentration and RoR

A
  • at low substrate concs, the active sites of enzymes are not all used
  • as the substrate concs increase, more active sites come into use
  • this means that substrate concs are the limiting factor
  • when all active sites are being used, increasing substrate conc cannot increase the RoR
  • the enzyme conc becomes the limiting factor
39
Q

explain the relationship between enzyme concentration and RoR

A

-RoR increases until the enzymes are limited by the conc of the substrate

40
Q

important properties of water

A
  • high specific heat capacity
  • good solvent
  • metabolite
  • strong cohesion
  • large latent heat of vaporisation
41
Q

describe the high specific heat capacity of water

A
  • buffers changes in temperature so minimises temperature fluctuations in living things
  • helps organisms avoid changes in their internal temp and provides stability for enzymes
42
Q

describe water being a good solvent

A
  • is an important solvent in which metabolic reactions occur

- allows gases to easily diffuse as well as enzymes and waste products

43
Q

describe water being a metabolite

A

-metabolites are necessary for metabolic reactions such as condensation and hydrolysis

44
Q

describe water having strong cohesion

A

-this supports columns of water in the xylem and phloem and produces surface tension where water meets air.

45
Q

describe water having a large latent heat of vaporisation

A

-providing a cooling effect with little loss of water through evaporation

46
Q

what does ATP consist of

A

-ribose, adenine and 3 phosphate groups

47
Q

what is metabolism

A

all of the chemical reactions which take place in a cell

48
Q

properties of ATP

A
  • it is not stored
  • it is an immediate source of energy for biological processes
  • the bonds between the phosphate groups are high energy bonds. hydrolyzing it releases small amounts of energy
49
Q

equation of ATP being formed from ADP

A

ADP + Pi ATP

  • condensation of ADP and Pi is catalysed by ATP synthase
  • hydrolysis of ATP is catalysed by ATP hydrolase
50
Q

what can the inorganic phosphate released during the hydrolysis of ATP be used for

A
  • it can be used to phosphorylate other compounds

- this can make them more reactive

51
Q

ATP properties which make it a good energy source

A
  • energy released in small manageable amounts so no energy is wasted
  • small and soluble so it is easily transported around the cell
  • broken down in one step so energy can be released very quickly and simply
  • can transfer energy to another molecule by transferring one of its phosphate groups
  • can’t pass out of the cell so the cell always has an immediate supply of energy
52
Q

why is ATP more suitable to be an immediate source of energy

A
  • glucose can easily pass out of the cell - not immediately supplied
  • glucose does not release energy in small, manageable amounts so energy may be wasted
  • glucose not hydrolysed in one step - needs several bonds broken
53
Q

describe how ATP is synthesised

A
  • in the cell, ATP is synthesised from ADP and inorganic phosphate, catalysed by ATP synthase. this reaction produces energy
  • the energy is stored as chemical energy in the phosphate bond
  • ATP then diffuses to the part of the cell that need energy
54
Q

what is RNA

A

-a polymer of a nucleotide formed of ribose, a nitrogenous base and a phosphate group.

55
Q

how does a DNA double helix form

A

-a DNA molecule is a double helix with two polynucleotide chains held together by hydrogen bonds between specific complementary base pairs.

56
Q

function of DNA helicase

A

-unwinds DNA by breaking H bonds

57
Q

function of DNA polymerase

A

-catalyses the formation of phosphodiester bonds between nucleotides

58
Q

define semi-conservative replication

A

-each replicated DNA molecule contains one old strand and one new strand. each parent strand is used as a template.

59
Q

experiment proving semi-conservative replication

A
  • e-coli is grown in the presence of a heavy isotope of N, 15N.
  • this makes the e-coli DNA heavy
  • the e-coli is then transferred to a solution containing the lighter 14N isotope
  • after one generation, the DNA is centrifuged and this is repeated after each generation
60
Q

where does the pellet form in each generation of centrifugation

A
  • parent DNA contains 100% heavy DNA
  • 1st generation DNA contains 100% medium density DNA
  • 2nd generation DNA contains 50% light and 50% medium density

Biology (9 decks)

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