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
chemical elements found in nucleic acids
* carbon
* hydrogen
* oxygen
* nitrogen
* phosphorous
26
function of monosaccharides
* main function is to produce and store energy
* building blocks of more complex sugars that are used as structural elements
27
structure of alpha glucose
* hexose monosaccharide
* 6 carbon, 12 hydrogen, 6 oxygen
* structural cis isomer
28
properties of alpha glucose
* building block of glycogen & starch
* main sugar used in respiration
* soluble, easily transported in respiration
29
structure of beta glucose
* hexose monosaccharide
* 6 carbon, 12 hydrogen, 6 oxygen
* structural trans isomer
30
function of beta glucose
* polymerise to make cellulose
* essential polysaccharide used in the structure of plants
31
difference between alpha and beta glucose
* alpha glucose hydroxyl group is below carbon 1
* beta glucose hydroxyl group is above carbon 1
* humans can't digest beta glucose
32
structure of ribose
* pentose monosaccharide
* ring structure
* 5 carbon, 10 hydrogen, 5 oxygen
33
function of ribose
* forms the backbone of ribonucleic acid (RNA)
* essential in energy production
34
difference between hexose and pentose monosaccharide
* hexose has 6 carbon atoms
* pentose has 5 carbon atoms
35
disaccharides
* condensation forms glycosidic bonds between two monosaccharides
* sucrose, galactose, maltose
* all have molecular formula of C12H22O11
36
sucrose
* 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
lactose
* joined by 1,4 beta glycosidic bond
* glucose + galactose
* sugar found in the mlik of mammals
* milk sugar
38
maltose
* 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
polysaccharides
* glycogen
* starch
* cellulose
40
structure of polysaccharides
* polymers made up of multiple glucose monosaccharides connected by ether bonds
* condensation of alpha or beta glucose
41
function of polysaccharides
* providing structural support
* storing energy
* sending cellular communication signals
42
structure of starch
* mixture of two polysacchardies - amylose and amylopectin
* very compact molecule
* linked by glycosidic bonds in a condensation reaction
43
function of starch
* key energy store in plants
* insouble, doesn't affect water potential in cells
* storage polymer of alpha glucose in plant cells
44
structure of amylose
* unbranched polymer
* glucose monomers joined by 1,4 glycosidic bonds
* helix with intermolecular hydrogen bonds
45
function of amylose
* 20% of starch
* glucose released by enzyme action at both ends of polymer (slower release)
46
structure of amylopectin
* branched polymer
* glucose monomers joined by 1,4 and 1.6 glycosidic bonds
47
function of amylopectin
* 80% of starch
* glucose released by enzyme action at all ends of the polymer (rapid release)
48
structure of glycogen
* formed from many molecules of alpha glucose joined together by 1, 4 and 1, 6 glycosidic bonds
* branched, insoluble, compact
49
function of glycogen
* a reserve source of energy for the body, providing quick energy when needed
* main storage polymer of alpha glucose found in animal cells
50
structure of cellulose
* 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
function of cellulose
* polymer of beta glucose gives rigidity and structural support for plant cell walls
52
5 functions of lipids
* energy storage
* hormones
* solvent
* thermal insulation
* buoyancy
53
formation of trigylcerides
* condensation reaction
* 1 molecule of glycerol and 3 fatty acids
* forms 3 ester bonds
54
functions of triglycerides
* high energy : mass ratio
* insouble hydrocarbon chain
* slow conductor of heat
* less dense than water
55
functions of fatty acids
* hydrophobic
* grouped together
* non-polar - no charge
56
saturated fatty acids
* only single bonds
* straight chain molecules - many contact points
* higher melting point - solid at room temperature
* found in animal fats
57
unsaturated fatty acids
* double carbon bonds
* kinked molecules - fewer contact points
* lower melting point - liquid at room temperature
* found in plant oils
58
structure of phospholipids
* glycerol backbone attached to two hydrophobic fatty acids and a hydrophilic polar phosphate head
59
function of phospholipids
* forms phospholipid bilayer in water - component of membranes
* tails can splay outwards - waterproofing for skin
60
