biological molecules Flashcards
1
Q
what are organic compounds
A
carbon-containing compound that are found in living organisms
2
Q
what do organic compounds contain
A
carbon and hydrogen
3
Q
examples of inorganic compounds
A
- hydrogen carbonates (HCO₂⁻)
- carbonates (CO₃²⁻)
- oxides (CO, CO₂)
4
Q
organic compounds are
A
- all macromolecules
- large molecules
- composed of mainly covalently connected atoms
5
Q
groups of organic macromolecules
A
- carbohydrates
- fats/lipids
- proteins
6
Q
importance of organic macromolecules
A
- aid organisms to grow, sustain and reproduce
- involved in building organisms from single cells to complex living beings by interacting with each other
7
Q
what are polymers
A
macromolecules that has sub-units/monomers
8
Q
examples of polymers
A
- carbohydrates
- proteins
9
Q
what is polysaccharide made up of
A
- monosaccharide
- disaccharide(2 monosaccharide together)
10
Q
sub-unit of polysaccharides
A
glucose
11
Q
sub-unit of proteins
A
amino acids
12
Q
why aren’t lipids polymers
A
has no sub-units/monomers
13
Q
examples of substances made up of lipids
A
- fats
- oils
- steroids
14
Q
types of carbohydrates
A
- simple sugars
- complex carbohydrates
15
Q
features of simple sugars
A
- readily soluble in water
- exerts osmotic pressure
- sweet to taste
16
Q
types of simple sugars
A
- single sugar
- double sugar
17
Q
what are simple sugars made up of
A
monosaccharides
18
Q
examples of single sugars
A
- glucose
- frutose
- galactose
- ribose
19
Q
what are double sugars made up of
A
disaccharides
20
Q
examples of double sugars
A
- sucrose
- maltose
- lactose
21
Q
what is sucrose made out of
A
- glucose
- frutose
22
Q
what is maltose made out of
A
2 glucose
23
Q
what is lactose made out of
A
- galactose
- glucose
24
Q
features of complex carbohydrates
A
- insoluble in water
- does not exert osmotic pressure
- does not taste sweet
25
what are complex carbohydrates made up of
polysaccharides
26
examples of complex carbohydrates
- starch
- glycogen
- cellulose
27
properties of glucose
- soluble in water
- posesses remarkable chemical stability under physiological conditions
- 6 sides
28
why are glucose soluble in water
contains hydroxyl (-OH) that readily form hydrogen bonds
29
purpose of glucose being soluble in water
- ensures efficient transport within aqueous biological fluids (blood, sap)
- facilitates its movement across cellular environments, enabling glucose to serve as a universal energy source
30
how does facilitated diffusion affect the transportability of glucose
- further enhanced transportability
- allows it to move across plasma/cell membranes efficiently
31
how many sides does frutose have
5
32
what is the bond that combines 2 glucose together to form maltose
glycosidic bond
33
through pathways such as glycolysis and cellular respiration,
- complete oxidation of a single glucose molecule generates substantial amounts of ATP
- makes it an indispensable substrate for sustaining cellular functions
34
what is the reaction that produces disaccharides from 2 monosaccharides
condensation
35
how to break the glycosidic bond (covalent bond)
hydrolysis
36
what is hydrolysis
adding one molecule of water to break a covalent bond
37
what are polysaccharides composed of
many monosaccharides linked together through condensation
38
what are polysaccharides
polymers of monosaccharides
39
what can polysaccharides occur as
long/straight/branched chains
40
structure of starch
made up of several thousand glucose molecules joined together
41
role of starch
It is a storage form of carbohydrates in plants. When needed, it can be digested to glucose to provide energy for cell activities.
42
where is starch found
storage organs of plants, e.g. potato tubers and tapioca
43
structure of cellulose
made up of many glucose molecules that are alternatively inverted and joined through glycoscidic bonds
44
role of cellulose
- the cellulose cell wall protects plant cells from bursting or damage
- cellulose cannot be digested in our intestines. They serve as dietary fibre that prevents constipation.
45
where is cellulose found
cell walls of plants
46
structure of glycogen
Branched molecule made of many glucose molecules joined together by glycoscidic bonds
47
role of glycogen
a storage form of carbohydrates in mammals. When needed, it is digested to glucose to provide energy for cell activities.
48
where is glycogen found
Stored in the liver and muscles of mammals
49
how do plants store glucose
in the form of starch
50
where do animals get their carbohydrates
from plants in the form of starch
| (animals cannot store/make starch in our body)
51
what is the main store of glucose in animals
glycogen
| (stored mainly in the liver and muscles)
52
why is glycogen and starch suitable as storage materials in cells
- They are insoluble in water, so they do not change the water potential in the cells.
- They are large molecules that cannot diffuse through cell membranes, so they will not be lost from the cell.
- They can easily be easily broken down to glucose when needed, for example, in tissue respiration.
- Their molecules have compact shapes, so they occupy less space than all the individual glucose molecules that make up a glycogen or starch molecule.
53
functions of carbohydrates
- as a substrate for respiration, to provide energy for cell activities
- to form supporting structures, for example, cell walls in plants
- to be converted into other organic compounds such as amino acids
- for the formation of nucleic acids, for example, DNA
- to synthesise lubricants, for example, mucus, which consists of a carbohydrate and a protein
- to synthesise the nectar in some flowers. Nectar is a sweet liquid that plants produce to attract insects
54
what does lipids include
- fat
- oils
- wax
- steroids
- phospholipids
55
what is a major group of lipids
triglycerides
56
lipids dissolve in
non-polar solvents
57
examples of non-polar solvents
- chloroform
- ether
- benzene
58
how are lipids able to dissolve in non-polar solvents
they have a predominantly non-polar nature, hydrophobic, which allows them to interact effectively with similar molecules
59
function of fats
- A source and a long-term storage of energy.
- An insulating material that prevents excessive heat loss.
- A solvent for fat-soluble vitamins and many other vital substances such hormones
- An essential part of cells, especially in cell membranes.
- A way to reduce water loss from the skin surface. Glands in the skin secrete an oily substance.
60
how do fats have a long-term storage of energy
They are a suitable long-term storage material because fats have a higher energy value compared to carbohydrates.
61
example of how fat is an insulating material
animals such as seals have a thick layer of fat (blubber) beneath the skin, which helps to reduce loss of body heat
62
how are fats able to reduce water loss
- This oily substance forms a thin layer over the skin surface, reducing the rate of evaporation of water.
- The oily substance also reduces the rate of heat loss from the skin.
63
what is the purpose of lipids being hydrophobic
- solubility in water is minimal
- influences their behaviour in biological systems
64
what are triglyceride molecules made up of
- 3 fatty acids
- 1 glycerol
65
all triglycerides are
- macromolecules
- but not polymers
66
word equation to show the formation of a triglyceride molecule
glycerol + 3 fatty acids → triglyceride + 3 water molecules
67
how is the bond between the glycerol molecule and each fatty acid molecule is formed
- the molecules undergo a condensation reaction
- water molecules are formed as a by-product
68
type of enzymes that catalyses the breakdown of triglycerides
lipases
69
what are proteins made up of
- carbon
- hydrogen
- oxygen
- nitrogen
- sulfur (may be present)
70
amino acids is made up of
an amino group (-NH₂), an acidic group (-COOH) and a side chain
(denoted by R, which may sometimes contain sulfur).
71
amino acids are linked together by _
condensation to form polypeptides
72
what is the bond between 2 amino acids
- peptide bond
- covalent bond
73
2 amino acids =
- 1 covalent bond
- 1 condensation reaction
74
what happens when 2 amino acids undergo condensation
- OH (amino acid 1) and H (amino acid 2) is removed
- OH and H form water
- forms peptide bond
75
what forms the peptide bond
O
||
C - N
|
H
76
difference between polypeptide and protein
protein is functional, polypeptide isn't
77
how is protein formed from amino acids
1. Many amino acid molecules are joined in a linear manner to form a polypeptide.
2. the polypeptide chains are folded into a more complex, three-dimensional shape.
78
proteins are used in the
- synthesis of new cytoplasm, for growth and repair of worn-out body cells
- synthesis of enzymes and some hormones
- formation of antibodies to combat diseases
79
how is the formation of polypeptide formed
combination between many amino acids
80
2 types of amino acids
- essential
- non-essential
81
whats special about essential amino acids
- human body cannot synthesize internally
- inability stems from the lack of specific enzymes or metabolic pathways needed to produce these compounds
82
where is essential amino acids obtained
dietary sources
83
examples of dietary sources
- meat
- dairy
- eggs
- legumes
- nuts
84
purpose of essential amino acids
- protein synthesis
- tissue repair
- various metabolic processes essential for growth, immune function and overall health
85
where is non-essential amino acids obtained
synthesized by the body, even if they are not directly consumed in the diet
86
when does the body produce non-essential amino acids
metabolic processes involving other amino acids or intermediates
87
purpose of non-essential amino acids
physiological functions
88
why is having a diet that contains all amino acids important
ensures the body has the building blocks for all necessary proteins
89
what happens if there is a deficiency in an amino acid
impair protein synthesis and disrupt bodily functions
90
what is denaturation
loss of the specific 3 dimensional conformation of a protein molecule
91
when does denaturation occur
some of the bonds, which normally maintain the proteins 3D structure are broken
92
what happens when denaturation occurs
molecule to unfold and change shape and hence lose its biological function or activity
93
if the protein is a enzyme
the 3D conformation of the enzymes active site would be lost and the enzyme will lose its function
94
types of denaturation
- permenant
- temporary
95
how can the proteins conformation of the protein molecule resume
as long as the primary structure of the protein is unaffected, the specific 3D conformation of the protein molecule can resume if the agents to cause denaturation is removed
96
how to turn denaturated protein into normal protein
renaturation
97
examples of agents that may cause denaturation
- heat
- strong acids and alkalis
- high concentration of salts
98
how does heat cause denaturation
when kinetic energy is supplied to the protein, it causes the atoms in the proteins to vibrate violently, disrupting the weak hydrogen bonds, ionic bonds and hydrophobic interactions, which help to maintain the 3D conformation of the protein
99
what is the outcome of heat supplied to protein
causes the protein to cogulate
100
what is cogulate
the exposed positive and negative charges of amino acids attract
101
how does strong acids and alkalis + high concentration of salts cause denaturation
the additional H⁺ ions in acids can combine with COO⁻ groups of the amino acids to fomr COOH, causing the ionic bonds to be broken
