Biological molecules Flashcards
1
Q
chemical bond
A
- two or more elements sharing a bond through electrons
2
Q
covalent bond
A
- non- metals sharing electrons with a strong bond
3
Q
single bond
A
- sharing one pair of electrons
4
Q
double bond
A
- sharing two pairs of electrons
5
Q
non-polar covalent bond
A
- chemical bond that is formed when electrons are shared equally between two atoms
6
Q
polar covalent bond
A
- chemical bond that is formed when electrons are not equally shared between two atoms
7
Q
hydrogen bond
A
- when a hydrogen atom is covalently bonded to one electronegative atom to another nearby electronegative atom
8
Q
polarity
A
- uneven sharing of electrons
9
Q
polar
A
- contains a positively and negatively charged region
10
Q
dipolar
A
- two charged regions
11
Q
hydrophilic
A
- substances dissolve in water easily
- (water loving)
12
Q
hydrophobic
A
- substances do not dissolve in water
- (water hating)
13
Q
6 properties of water
A
- solvent / metabolite
- cohesive
- high surface tension
- high specific capacity and latent heat vaporisation
- incompressible
14
Q
4 roles of water
A
- solvent
- transport medium
- coolant
- habitat
15
Q
monomer
A
- smaller units that join together to form larger molecules
16
Q
example of monomers
A
- monosaccharides
- amino acids
- nucleotides
17
Q
structure of monosacchrides
A
- formula is (CH2O) n
- consists of single unit which contains carbon chain of three to six carbon
- combine through glycosidic bonds to form larger carbohydrates
18
Q
polymer
A
- molecules formed when many monomers join together
19
Q
example of polymers
A
- polysaccharides
- proteins
- DNA / RNA
20
Q
condensation
A
- chemical bond that forms between two molecules
- a molecule of water is produced
21
Q
hydrolysis
A
- a water molecule is used to break a chemical bond between two molecules
22
Q
chemical elements found in carbohydrates
A
- carbon
- hydrogen
- oxygen
23
Q
chemical elements found in lipids
A
- carbon
- hydrogen
- oxygen
24
Q
chemical elements found in proteins
A
- carbon
- hydrogen
- oxygen
- nitrogen
- sulfur
25
Q
chemical elements found in nucleic acids
A
- carbon
- hydrogen
- oxygen
- nitrogen
- phosphorous
26
Q
function of monosaccharides
A
- main function is to produce and store energy
- building blocks of more complex sugars that are used as structural elements
27
Q
structure of alpha glucose
A
- hexose monosaccharide
- 6 carbon, 12 hydrogen, 6 oxygen
- structural cis isomer
28
Q
properties of alpha glucose
A
- building block of glycogen & starch
- main sugar used in respiration
- soluble, easily transported in respiration
29
Q
structure of beta glucose
A
- hexose monosaccharide
- 6 carbon, 12 hydrogen, 6 oxygen
- structural trans isomer
30
Q
function of beta glucose
A
- polymerise to make cellulose
- essential polysaccharide used in the structure of plants
31
Q
difference between alpha and beta glucose
A
- alpha glucose hydroxyl group is below carbon 1
- beta glucose hydroxyl group is above carbon 1
- humans can’t digest beta glucose
32
Q
structure of ribose
A
- pentose monosaccharide
- ring structure
- 5 carbon, 10 hydrogen, 5 oxygen
33
Q
function of ribose
A
- forms the backbone of ribonucleic acid (RNA)
- essential in energy production
34
Q
difference between hexose and pentose monosaccharide
A
- hexose has 6 carbon atoms
- pentose has 5 carbon atoms
35
Q
disaccharides
A
- condensation forms glycosidic bonds between two monosaccharides
- sucrose, galactose, maltose
- all have molecular formula of C12H22O11
36
Q
sucrose
A
- joined by alpha 1,4 glycosidic bond
- glucose + fructose
- used in many plants for transporting food reserves
- transported from leaves to other parts of plants
- table sugar
37
Q
lactose
A
- joined by 1,4 beta glycosidic bond
- glucose + galactose
- sugar found in the mlik of mammals
- milk sugar
38
Q
maltose
A
- joined by alpha 1,4 glycosidic bond
- glucose + glucose
- first product of starch digestion
- further broken down to glucose before being absorption in the human gut
39
Q
polysaccharides
A
- glycogen
- starch
- cellulose
40
Q
structure of polysaccharides
A
- polymers made up of multiple glucose monosaccharides connected by ether bonds
- condensation of alpha or beta glucose
41
Q
function of polysaccharides
A
- providing structural support
- storing energy
- sending cellular communication signals
42
Q
structure of starch
A
- mixture of two polysacchardies - amylose and amylopectin
- very compact molecule
- linked by glycosidic bonds in a condensation reaction
43
Q
function of starch
A
- key energy store in plants
- insouble, doesn’t affect water potential in cells
- storage polymer of alpha glucose in plant cells
44
Q
structure of amylose
A
- unbranched polymer
- glucose monomers joined by 1,4 glycosidic bonds
- helix with intermolecular hydrogen bonds
45
Q
function of amylose
A
- 20% of starch
- glucose released by enzyme action at both ends of polymer (slower release)
46
Q
structure of amylopectin
A
- branched polymer
- glucose monomers joined by 1,4 and 1.6 glycosidic bonds
47
Q
function of amylopectin
A
- 80% of starch
- glucose released by enzyme action at all ends of the polymer (rapid release)
48
Q
structure of glycogen
A
- formed from many molecules of alpha glucose joined together by 1, 4 and 1, 6 glycosidic bonds
- branched, insoluble, compact
49
Q
function of glycogen
A
- a reserve source of energy for the body, providing quick energy when needed
- main storage polymer of alpha glucose found in animal cells
50
Q
structure of cellulose
A
- made up of unbranched chains of glucose molecules linked via beta 1-4 glycosidic bonds
- straight chain, unbranched molecule
- alternate glucose molecules are rotated 180
- high tensile strength
51
Q
function of cellulose
A
- polymer of beta glucose gives rigidity and structural support for plant cell walls
52
Q
5 functions of lipids
A
- energy storage
- hormones
- solvent
- thermal insulation
- buoyancy
53
Q
formation of trigylcerides
A
- condensation reaction
- 1 molecule of glycerol and 3 fatty acids
- forms 3 ester bonds
54
Q
functions of triglycerides
A
- high energy : mass ratio
- insouble hydrocarbon chain
- slow conductor of heat
- less dense than water
55
Q
functions of fatty acids
A
- hydrophobic
- grouped together
- non-polar - no charge
56
Q
saturated fatty acids
A
- only single bonds
- straight chain molecules - many contact points
- higher melting point - solid at room temperature
- found in animal fats
57
Q
unsaturated fatty acids
A
- double carbon bonds
- kinked molecules - fewer contact points
- lower melting point - liquid at room temperature
- found in plant oils
58
Q
structure of phospholipids
A
- glycerol backbone attached to two hydrophobic fatty acids and a hydrophilic polar phosphate head
59
Q
function of phospholipids
A
- forms phospholipid bilayer in water - component of membranes
- tails can splay outwards - waterproofing for skin
60
Q
A
