Brainscape's Knowledge GenomeTM

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


See full index

OCR A Biology Module 2 > Biological molecules > Flashcards

Biological molecules Flashcards

1
Q

cations and their roles

A
  • Ca+: nerve impluse transmission+muscle contraction
  • Na+: nerve impluse transmission+kidney function
  • K+: nerve impluse transmission+stomatal opening
  • H+: catalysis of reactions+pH determination
  • NH4+: production of nitrate ions by bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

anions and their roles

A
  • NO3-: nitrogen supply for amino acid and protein formation
  • HCO3-: maintanence of blood pH
  • Cl-: balance + charges of Na and K ions in cells
  • PO4 3-: cell membrane formation+nucleic acid & ATP formation+bone formation
  • OH-: catalysis of reactions+pH determination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is a monomer?

A

small units which are the components of larger molecules eg. nucleotides, amino acids

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

what is a polymer?

A

molecules made from monomers joined together.

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

importance of condensation+hydrolysis reactions

A
  • condensation: building up large molecules e.g. glucose to glycogen for storage.
  • hydrolysis: breakdown of large, insoluble molecules into smaller, soluble molecules e.g. glycogen to glucose for respiration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

elements that make up biological molecules

A
  • carbs/lipids=C, H, O
  • proteins=C, H, O, N, S
  • nucleic acids=C, H, O, N, P
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are monosaccharides?

A

simple sugars made of a single sugar molecule
very soluble+form sweet solutions
general formula: (CH^2O)n

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

role of monosaccharides in living organisms

A
  • source of energy in respiration: lots of C-H=give high yield of energy=released when bonds are broken=make ATP from ADP (ATP=key energy molecule in most organisms)
  • building blocks to make larger molecules eg. glucose polymerised to make polysaccharides starch, cellulose, glycogen; ribose=makes ATP+RNA; deoxyribose=DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is glycosidic bond?

A

any bond between sugars

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

condensation+hydrolysis in carbohydrates

A
  • condensation: water molecule released, new covalent bind formed, dimer/polymer formed
  • hydrolysis: water molecule used, covalent bond broken, smaller molecules formed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how are monosaccharides named?

A

based on no. of Cs in molecule
trioses=3C, pentoses=5C, hexoses=6C

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

what are disaccharides made of?

A
  • sucrose=alpha glucose+fructose
  • maltose=2 alpha glucose
  • lactose= alpha glucose+galactose
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

structure of starch

A
  • mixture of amylose+amylopectin=very large grains=fiund in storage organs+chloroplasts
  • amylose=made by lots of alpha glucose molecules ->curved+curled up chain=max. glucose molecules stored in min. space
  • amylopectin=shorter main chain of alpha 1, 4 bonds with side chains of 1, 6 bonds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

structure of glycogen

A
  • storage polysaccharide
  • similar to amylopectin but has more 1,6 bonds=more branches
  • glycogen granules=energy stores in liver+muscle cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

structure of cellulose

A
  • structural polysaccharide
  • very strong=ideal for reinforcing structures
  • polymer of beta glucose
  • hydrogen bonds between cellulose fibres=immensely strong tgt
  • cellulose fibres linked with other molecules to form bundles=microfibrils which join to form fibril
  • cellulose fibres=permeable=allow water+dissolved solutes
  • cell wall=resist turgor pressure+support plant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

benedict test

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

structure of triglycerides

A
  • 1 glycerol+3 fatty acids
  • join by condensation reactions between hydroxyl groups
  • ester bond formed
  • insoluble in water=hydrophobic but soluble in organic solvents eg. alcohol
  • fatty acids=long chains w even spread of electric charge=hard to mix w eachother
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

types of fatty acids

A
  • saturated
  • straight chain=tightly packed=up mp=solid at room temp
  • eg. animal lipids (fats)
  • unsaturated
  • have C=C double bond=x contain max. no. of hydrogens
  • kinks in chains=difficult to slot together=loosely packed=down mp=liquid at room temp
  • eg. plant lipids (oils)
19
Q

roles of lipids (triglycerides)

A
  • energy source+reserve=contain many C-H bonds=higher energy yield than carbs
  • insulator against heat loss+electrical insulation around nerves
  • provides buoyancy (floating)
  • mwtabolic source of water when used in respiration
  • protection
20
Q

structure of phospholipids

A
  • one hydrphillic phosphate head+2 hydrophobic fatty acid tails
  • one soluble end and one insoluble end
  • when forced underwater form:
  • micelle or bilayer sheet=phosphate head touches water, tails dont
21
Q

role of phospholipids

A
  • formation of phospholipid bilayer of plasma membranes
22
Q

structure of cholesterol

A
  • made of 4 carbon rings
  • very hydrophobic=insoluble in water (but OH-=hydrophillic/polar)
23
Q

roles of cholesterol

A
  • found in membranes and regulates their fluidity ans strength
  • used as a precursor for makinf testerone, oestrogen, vitamin D
24
Q

lipids test

A
25
Q

structure of proteins

A
  • amino acids joined by condensation reaction b/w OH+H=forms peptide bond
26
Q

levels of protein structure

A
  • primary structure
  • a list of amino acids in a protein in the right order
  • secondary structure
  • R groups of ami
  • tertiary structure
  • quaternary structure
27
Q

Structure and function of globular proteins

A
  • structure
    Proteins curl into a ball shape with hydrophobic R-groups pointing to the centre=soluble=found in many tissue fluid
  • function
    Have various roles in metabolism eg. Enzymes, carrier molecules
28
Q

Function of globular proteins

A
  • Enzymes
    globular proteins=shape can be altered appropriately to fit their active sites with high specificity eg. Lipase
  • Transport proteins
    soluble=function well as transport proteins as they can cross cell membranes eg. Haemoglobin
  • Messengers proteins/hormones
    Soluble=work well as hormones=regulate body’s metabolic processes eg. Insulin
29
Q

Haemoglobin: structure+function

A

Structure
- globular conjugated protein
- quaternary structure=4 polypeptide chains (globin proteins)=2 α+2 β chains=each has a prosthetic haem (Fe 2+) grp (reacts reversible w O2)
- chains held by disulphide bonds+hydrophobic R-groups in=preserves 3D shape & hydrophilic out=maintains solubility
- carries 4 O2 molecules due to 4 haem group

Function
- binds with O2 in lungs+transports it bld
- soluble=carries O2 more efficiently as O2=insoluble in H2O
- haem grp=allow small molecules eg. O2 to bind easier=alter tertiary/quaternary structure=up affinity for other O2 molecules=bind easier

30
Q

Structure of fibrous proteins

A
  • long, thin strands=long polypeptide chains=twist tgt
  • insoluble=hydrophobic parts x folded inward
31
Q

Function of fibrous proteins

A
  • structural proteins=stable+insoluble=support+protect tissues eg. Keratin (structure to hair+nails), collagen (connective tissue), elastin (elastic connective tissue)
32
Q

Collagen: structure+function

A
  • structure
    3 polypeptide chains held tightly tgt by H-bonds+covalent bonds in a triple helix=tropocollagen
    Each chain=helix shape (NOT α helix)
  • function
    Cross-links hold collagen molecules tgt=fibrils
    Molecules are positioned in fibrils to have staggered ends
    Grp of fibrils=collagen fibres=positioned to line up w forces they withstand=provide support+tensile strength
  • found in skin, muscles, tendons, bones
33
Q

Proteins test

A
34
Q

Paper/thin layer chromatography

A

Rf values

35
Q

ATP: function+properties

A
  • properties
    Universal energy currency
    Small=lots of it can be stored+move quickly
    Water soluble as most reactions occur in cytoplasm+ATP has to be next to them
    Bonds bw phosphate grips=unstable, low Ea=easily broken
    Releases energy in small quantities=more stable energy lvls
    Easily regenerated=readily available
    Phosphate can phosphorylate other compounds=makes them more reactive
  • function
    ATP+H2O —> ADP+Pi
    catalysed by ATP hydrolase and releases energy for use in cells
    ADP+Pi —> ATP+H2O
    Catalysed by ATP synthase & requires energy and traps chemical energy in the bond
36
Q

Structure of water

A
  • dipolar molecule
    The Hs have a delta+ charge, O have a delta- charge=positive and negative poles
  • water molecules form H-bonds w each other (one O with 2 H)
37
Q

Roles of water

A
  • solvent=substances dissolve in it
  • temp control=buffer sudden temp changes
  • cooling mechanism=mammals use evaporation of water in sweat to cool skin
  • habitat=organisms survive+reproduce in it
  • metabolite=chemical reactions involve it
  • transport= use it to move substances
38
Q

Water as a solvent

A
  • most substances in cells=ionic compounds=split apart when added to H2O=negative ions attracted to H+ and positive ions to O2- = ions surrounded by water=compound dissolves
  • useful bc
    Biological reactions occur in solution eg. Cytoplasm of eukaryotes/prokaryotes
    Dissolved substances can be transported around the body eg ions in plasma
39
Q

Water as temp buffer

A
  • high SHC=resistant to rapid changes in temp
    As many organisms are made up of water=body can maintain a stable temp
40
Q

Water as a cooling mechanism

A
  • H-bonds bw water molecules=a lot of energy needed to evaporate water due to high LH of vaporisation=lots of energy needed to break H-bonds to go from liquid to gas
  • useful bc
    Organisms can use evaporation of water as a cooling method w/o losing too much water
41
Q

Water as a habitat

A
  • high SHC+high LH of vaporisation=x change temp easily=stable environment for organisms to live in
  • ice less dense than water as molecules are further apart=ice floats=insulating layer at surface=water below freeze=allowing organisms to survive
42
Q

Water as metabolite

A

Involved in many chemical organisms inside organisms eg. Hydrolysis, condensation, photosynthesis

43
Q

Water as a transport medium

A
  • cohesion=tendency of water molecules to stick tgt
  • adhesion=tendency of water to stick to other materials
    This allows water to flow through organisms, carrying substances along w it eg. In the xylem of a plant
  • water molecules create high surface tension when they meet air=forms skin-like structure at water’s surface=string enough to support small organisms eg.pond-skaters

OCR A Biology Module 2 (5 decks)

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