Brainscape's Knowledge GenomeTM

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


See full index

Biology > Biological molecules > Flashcards

Biological molecules Flashcards

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

What is a monomer and examples

A

. smaller units that join to form larger molecules
. e.g
- monosaccharides
- amino acids
- nucleotides

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

what is a polymer and examples

A

= molecules formed when many monomers join together
e.g
- polysaccharides
- proteins
- DNA/RNA

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

condensation reaction?

A

. chemical bond forms between 2 molecules + h2o is produced

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

hydrolysis reaction?

A

. water molecule used to break chemical bond between 2 molecules

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

what are the 3 hexose monosaccharides?

A

. glucose
. fructose
. galactose

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

what type of bond forms when monosaccharides react?

A

.1,4/1,6 glycosidic bond
. 2 monomers form a disaccharide
. more than 2 monomers form a polysaccharide

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

name 3 disaccharides + how they form?

A

. glucose + glucose = maltose
. glucose + fructose= sucrose
. glucose + galactose= lactose

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

Difference in structure between alpha and beta glucose?

A

alpha- OH below plane of ring
beta- OH above plane of ring

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

structure and function of starch?

A

.function= storage polymer of alpha glucose in plant cells
. insoluble = wont affect water potential
. large= doesn’t diffuse out of cells
. made from amylose; 1,4 glycosidic bonds. helix with H bonds= compact
.and made from amylopectin; 1,4 and 1,6 glycosidic bonds. branched = many ends for hydrolysis into glucose

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

structure + function of glycogen?

A

function= main storage of alpha glucose in animal cells
structure;
. 1,4 + 1,6 glycosidic bonds
. branched= many ends for hydrolysis
. insoluble= wont affect water potential/ no osmotic effect
. compact

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

structure + function of cellulose?

A

function= polymer of beta glucose, provides strength to plant cell walls
structure;
. 1,4 glycosidic bonds
. unbranched molecule
. H bond crosslinks between parallel strands from microfibrils= high tensile strength

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

test for starch?

A

. add iodine to sample
. + result = orange to blue/ black

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

test for reducing sugars?

A

. add benedict’s reagent to sample
. heat in water bath for 5 minutes
. + result= blue to red

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

test for non reducing sugars?

A

. hydrolyse by adding HCL
. heat in water bath for 5 minutes
. neutralise solution using sodium carbonate solution
. do benedict’s test as usual

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

how could you use calorimetry to get qualitative results for the presence of sugars and starch?

A

. make standard solutions with known conc - record absorbance
. plot calibration curve
. use curve to read off conc

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

test for lipids?

A

. dissolve solid sample in ethanol
. add equal vol of water and shake
. + result= milky white emulsion forms

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

how do triglycerides form?

A

. condensation reaction between 1 molecule of glycerol and 3 fatty acids forms ester bonds

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

saturated vs unsaturated fatty acids?

A

saturated;
- single bonds
- straight chain molecules
- higher melting point = solid at RT
unsaturated;
- double bonds
- kinked molecules = fewer contact points
- lower mpt = liquid at RT

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

triglycerides structure + function?

A

. lots of energy: mass= high calorific value from oxidation
. insoluble hydrocarbon chain= doesn’t affect water potential
. slow conductor of heat= thermal insulation
. less dense than water= buoyancy of aquatic animals

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

structure + function of phospholipids?

A

. glycerol backbone attached to 2 hydrophobic fatty acid tails + 1 hydrophilic polar phosphate head
. forms phospholipid bilayer in water
. tails can spread outwards

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

structure of an amino acid?

A

. COOH (carboxyl) group
. NH2 ( amino) group
. R group

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

test for proteins?

A

. Add biuret reagent to sample
. + result= blue to purple

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

how do dipeptides and polypeptides form?

A

. condensation reaction forms peptide bonds
. dipeptide= 2 amino acids
. polypeptide= 3/ more amino acids

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

primary structure of a protein?

A

. sequence of amino acids in the polypeptide
. determined by sequence of codons on mRNA

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

secondary structure of a protein?

A

. specific 3D shape that protein takes due to H bonding between the amino acids

21
Q

2 types of secondary protein structure?

A

.Alpha (α) helix form due to coiling. Hydrogen bonding leads to coiling, forming a spiral, cylindrical (helical) shape.
.Beta (β) pleated sheets form due to folding. Hydrogen bonding leads to folding, forming an almost flat, but kinked sheet of amino acids. They are formed by two amino acids chains running anti-parallel to each other

22
Q

tertiary structure of a protein?

A

. 3D structure formed by further folding of polypeptide
3 types of bonds in it;
. disulfide bridges
. ionic bonds
. hydrogen bonds

23
Q

quaternary structure of a protein?

A

. additional folding of protein
. held together by same bonds as tertiary structure

24
Q

structure+ function of globular proteins?

A

function- involved in metabolic processes e.g enzymes + haemoglobin
structure;
. spherical + compact
. hydrophilic R groups face outwards + hydrophobic R groups face inwards = usually water soluble

25
Q

structure + function of fibrous proteins?

A

function- provides structure + support
structure - forms long chains/ fibres. insoluble in water

26
Q

chromatography process to identify the amino acids in a mixture?

A

. spot mixture onto pencil line using a capillary tube + place paper in solvent
. remove once solvent reaches near end of paper. amino acids move diff distances based of attraction to paper + solubility in solvent
. use UV light to see spots
. calc Rf value

27
Q

what are enzymes?

A

. biological catalysts that speed up a reaction by lowering the activation energy

28
Q

Induced fit model of enzymes?

A

.shape of a.s isn’t complementary to substrate
. A.s changes shape + binds to substrate forming an enzyme substrate complex
. This puts a strain on substrate bonds+ lowers activation energy

29
Q

How does substrate conc affect ROR?

A

. ROR increases initially
. After a while, enzyme active sites are saturated and no e-s complexed form - enzyme conc is limiting factor

30
Q

How does temp affect ROR?

A

. Rate increases as kinetic energy increases until optimum temp
. Above optimum+ ionic + H bonds in tertiary structure break so active site is no longer complimentary to substrate

31
Q

How does pH affect ROR?

A

. Above optimum and H+ / OH- ions interact with H + ionic bonds in tertiary structure - denatures active site

32
Q

Competitive inhibitor?

A

. Similar shape to substrate so can bind to a.s
. Doesn’t stop reaction so e-s complex forms when inhibitor is released
. Increasing substrate conc decreases their effect

33
Q

Non competitive inhibitor?

A

. Bind to allosteric site on outside of enzyme
. Triggers a.s to change shape so can stop reaction
. Increasing substrate conc won’t help

34
Q

Structure of a nucleotide

A

Phosphate group = circle
Pentose sugar= pentagon
Nitrogen containing base= rectangle

35
Q

Pentose sugars in DNA + RNA?

A

DNA= deoxyribose
RNA= ribose

36
Q

Role of DNA?

A

. Base sequence of genes codes for functional rna and amino acid sequence of polypeptides
. Genetic info determines inherited characteristics so influences structure+ function of organisms

37
Q

Role of RNA?

A

mRNA= complementary sequence to 1 gene from dna with non coding regions. Codons can be translated into a polypeptide by ribosomes
rRNA= component of ribosomes
tRNA= supplies complementary amino acid to mRNA codons during translation

38
Q

How do polynucleotides form?

A

Condensation reactions between nucleotides form strong phosphodiester bonds

39
Q

Structure of DNA?

A

. Double helix of 2 polynucleotide strands
. H bonds between complementary purine and pyrimdine base pairs on opposite strands; Adenine and thymine, guanine and cytosine

40
Q

Which bases are purine and which are pyrimdine?

A

A+G= 2 ring purine
T+C+U= 1 ring pyrimdine

41
Q

Structure+ function of DNA?

A

. Sugar phosphate backbone has lots of H bonds to provide stability
. Long molecule so stores lots of info
. Helix is compact for storage in nucleus
. Base sequence of triplets codes for amino acids
. Double stranded for semi conservative replication
. Complementary base pairing for accurate replication
. Weak H bonds break so strands separate for replication

42
Q

Structure of messenger RNA

A

. Long ribose polynucleotide
. Contains uracil not thymine
.single stranded+ linear

43
Q

How is structure of mRNA related to its functions?

A

. Breaks down quickly so no excess polypeptide forms
. Ribosome can move along strand+ tRNA can bind to exposed bases
. Can be translated into a specific polypeptide by ribosomes

44
Q

Structure of transfer RNA?

A

. Single strand of 80 nucleotides
. Anticodon on one side, amino acid on other;
- anticodon binds to complementary mRNA codon
- amino acid corresponds to anticodon

45
Q

Process of semi conservative DNA replication?

A

. DNA helicase breaks H bonds between base pairs
. Each strand acts as a template
.free nucleotides attach to exposes bases by complementary base pairing
. DNA polymerase catalyses condensation reactions that join adjacent nucleotides on new strand
. H bonds reform

46
Q

Meselson - Stahl experiment?

A

. Bacteria grown in a medium containing isotope 15N
. Some bacteria moved to a medium containing lighter isotope 14N.
. Samples extracted after 1+2 cycles of DNA replication
. Centrifugation formed a pellet. Heavier DNA settles at bottom of tube

47
Q

Structure of adenosine triphosphate?

A

. . Adenine with 3 phosphate groups

48
Q

Role of ATP?

A

. ATP hydrolase catalyses ATP-> ADP+ Pi
- energy released is coupled to metabolic reactions
- phosphate group phosphorylates compounds to make them more reactive

49
Q

How is ATP resynthesised in cells?

A

. ATP synthase catalyses condensation reaction between ADP+ Pi
. During photosynthesis and respiration

50
Q

Why is ATP suitable as the energy currency of cells?

A

. High energy bonds between phosphate groups
. Small amounts of energy released at a time so less energy wasted as heat
. Single step hydrolysis so energy available quickly
.Readily resynthesised

51
Q

Properties of water?

A

. Metabolite - in condensation+ hydrolysis reactions. Keeps organisms alive ( metabolic reactions)
. Solvent- allows gases to readily diffuses as well as enzymes and waste products e,g ammonia and urea
. High specific capacity- lots of energy required to break H bonds between water molecules. So minimises temp fluctuations so acts as a buffer in living things
. Large latent heat of vaporisation- evaporation of water provides a cooling effect with little water loss
. Strong cohesion- supports columns of water so surface tension at water air boundary is high

52
Q

What are inorganic ions and where are they found in the body?

A

= ions that don’t contain carbon atoms
. Found in cytoplasm + extra cellular fluid

53
Q

Role of hydrogen ions in body?

A

. H+ ions interact with h bonds + ionic bonds in tertiary structure of proteins which can cause them to denature

54
Q

Role of iron ions in body?

A

. Fe2+ bonds to porphyrin ring to form haem group in haemoglobin

55
Q

Role of sodium ions in body?

A

. Involved in co transport for absorption of glucose + amino acids in lumen of gut

56
Q

Role of phosphate ions in body?

A

Component of:
. DNA
. ATP
.NADP
.cAMP

Biology (7 decks)

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