What is the composition of nucleic acid?
Long chains of monomers called nucleotides
What is the composition of a nucleotide?
What differentiates between the different nucleotides?
The nitrogen bases are different
What is the difference in sugars in RNA and DNA?
DNA: Deoxyribose (no oxygen on C2)
What is the difference between the nitrogen bases in RNA & DNA?
Both have: Adenine, Guanine and Cytosine
RNA has: Uracil
DNA has: Thymine
What bonds hold DNA together?
Ester bonds between deoxyribose sugar and phosphate group
What bonds hold RNA together?
Phosphodiester bonds between ribose sugar and phosphate group
What gives DNA or RNA its structure?
The sequence of nitrogen bases i.e. RNA: A,C,G,U DNA: A,C,G,T
Can the sequence be in any order?
What is the secondary structure of DNA?
Exists as a double helix held together by hydrogen bonds
What nitrogen bases link with each other in a DNA double-helix?
A-T & G-C
What is the difference between the link A-T & G-C?
A-T has 2 Hydrogen bonds
G-C has 3 Hydrogen bonds
Does RNA also exist in a double helix?
No single strand, but is still folded via hydrogen bonds
What are the differences in roles between DNA & RNA?
DNA: Stores genetic information
RNA: Transmits information from DNA to synthesise proteins
What are the different types of RNA?
Messenger RNA, Transfer RNA and Ribosomal RNA
What does 2 processes does protein synthesis involve?
Transcription(nucleus): an mRNA copy of a DNA strand is produced and heads for the Ribosomes
Translation(cytoplasm): tRNA molecules bring amino acids to mRNA within ribosome to build a protein.
Is adenosine 5 triphosphate an important molecule?
Is there any difference between saccharides(sugars) and carbohydrates?
No they are one in the same
What are the different types of Carbohydrates?
Monosaccharides, Disaccharides and Polysaccharides
What are the 3 elements in a carbohydrate?
Carbon, Hydrogen and Oxygen
What does a Monosaccharide consist of?
-Usually 3-6 Carbon atoms
-A carbonyl group (C=O)
-Several Hydroxyl groups (O-H)
What is the difference between the important monosaccharides glucose, fructose and galactose?
They all have different structures, but are composed of C6H12O6
Which group of sugars does a Monosaccharide with 6 carbon atoms?
What kind of structure do most monosaccharides have?
A cyclic structure
What is a glycosidic bond and what does it connect?
It's a covalent bond bewteen 2 hydroxyl groups of 2 monosaccharides, that spits out a water molecule.
What 2 monosaccharides make maltose and where is it found?
-Glucose and Glucose
What 2 monosaccharides make lactose and where is it found?
-Glucose and Galactose
What 2 monosaccharides make Sucrose and where is it found?
-Glucose and Fructose
What are polysaccharides?
Polymers of Glucose
What is the difference between Cellulose, Starch and Glycogen?
Cellulose: Unbranched Chains
Starch: Some branches
Glycogen: Many Branches
Do Glycosidic bonds hold polysaccharides together as well?
Do glycolipids and proteins contain carbohydrates in them?
What are the 7 types of proteins? with examples
1) Structural: Collagen => tendons & cartilage
2) Contractile: Myosin & Actin muscle fibers
3) Transport: Haemoglobin=> transports oxygen
4) Storage: Ferritin stores iron in spleen/liver
5) Hormone: Insulin regulates blood sugar levels
6) Enzyme: Trypsin catalyzes hydrolysis of proteins
7) Protection: Immunoglobulins stimulate immune responses
What does protein consist of?
Amino acids(monomer) bonded together(polymer)
What is the general structure of an Amino acid?
The alpha carbon contains both an amino group(H2N) and a carboxylic acid group(COOH) and each of the 20 contain a different side group(R).
How do you know if amino acids are non-polar?
If the R group is a hydrocarbon i.e. only hydrogen and carbon
What is the difference between a neutral and charged polar amino acid?
It is neutral when the R group doesn't have either a carboxylic acid group(COOH, acidic) or an amine(NH2, basic)
How many amino acids are not synthesized by the body?
How are amino acids linked together to form peptide bonds?
When the carboxyl group of one amino acid joins to amino group of another amino acid. Not the side chain
What is the difference between a dipeptide,polypeptide and a protein?
What are the different structures of proteins ?
What is a primary protein structure?
Sequence of amino acids in a polypeptide chain
What is an alpha helix protein structure?
Corkscrew shape with hydrogen bonds between amino acids
What is a beta pleated sheet protein structure?
Polypeptide chains held side by side by Hydrogen bonds
What is a triple helix protein structure?
3 alpha helix woven together like a rope
Do any of the secondary protein structure utilise the R groups?
What bonds give a tertiary structure its globular shape?
They are bonds between R groups, which can be hydrophobic, hydrophillic, hydrogen bonds, Disulfide bonds and salt bridges
What is a quarternary protein structure?
2 or more subunits together
Are globular proteins solluble in water?
Yes as polar molecules orient themselves to outside when placed in water
What is protein denaturation?
Disruption of bonds in secondary, tertiary and quartery structure that causes biological activity to be disrupted
What are the 5 main functions of Lipids?
1) Storage of Energy
2) Source of Energy
3) Basic component of cell membranes
4) Chemical messengers; steroid hormones
What are the 2 types of lipids that contain fatty acids?
1) Triglycerides(fat storage molecule)
2) Phospholipids(Cell membrane
What is the name of the lipid that doesn't contain fatty acids?
Steroids (cholesterol and sex hormones)
What is a fatty acid?
Long chain hydrocarbon with a carboxyl group at the end, they are insoluble in water(non-polar) and can be saturated or unsaturated
What does being saturated and unsaturated mean in terms of melting point and state at room temperature?
-Saturated fatty acids; pack closely together to have a high melting point and are therefore solid at room temperature
-Unsaturated fatty acids; have kinks in the chains which causes them to have a low melting point and to be a liquid at room temperature.
Is it cis or trans isomers that cause a V shape?
Cis, trans causes relatively straight kink
What are omega 6 & 3 fatty acids and are they good for you or not?
Fatty acids with a double bond on Carbon 6, yes in moderation as too much causes bleeding and a little stops clots
What is Triglyceride composed of and what does it do?
-Glycerol and 3 fatty acids
-Storage in adipose tissue
What is a phospholipid composed of and what does it do?
-2 Fatty acids, glycerol, a phosphate grop(P04) and a small polar molecule
-It makes up a phospholipid bilayer i.e. a cell membrane
What does amphiphilic mean?
A molecule with a polar and a non-polar end
What is the basic structure of a steroid?
3 hexagons with a pentagon on the end
What is the composition of cholesterol and what does it do?
-Hydrocarbon ring with hydroxyl group attached to the steroid nucles
-Is a key component of the cell membrane that helps control fluidity
What happens when you have too much cholesterol in your body?
It can clog your arteries
What are the 2 types of sex hormones and what is their respective functions?
1) Androgens(Testosterone), Male sexual characteristics
2) Estrogens(Estradiol), Female sexual characteristics
What are the 2 types of coritcoid hormones in the body and what do they do?
Mineralcoricoids: electrolyte and water balance
Glucocorticoids: regulate carb and protein metabolism in the body
What determines whether or not a solvent can dissolve the solute?
If the intermolecular forces are strong enough to separate the intramolecular forces holding the molecule or ion together.
What determines whether or not a bond between two atoms is polar?
Polar covalent: 0.5-1.9
What is electronegativity?
The ability of an atom to draw electrons towards it, this value is strongest at top right.
What is a functional group?
A reactive group of atoms in a functional group
What are the 4 main functional groups?
1. R-OH (alcohol)
2. R-C=0 (carbonyl),
3.R -COOH (carboxyl, acid) C has a double bond to 1 oxygen
4. R-NH2 (amino, basic).
Are the 4 main functional groups polar or non-polar?
Are non-polar or polar molecules found in fats and oils?
What do double bonds in a molecule mean?
The more double bonds the less saturated it becomes, it also makes a kink in the chain which makes it easier too separated i.e. lower melting point
How are some proteins soluble in water, despite their size?
Proteins are huge molecules made up of long polypeptide chains with amino acid side chains, when in water(polar) they tend to fold in on themselves and polar ends face outwards allowing it do dissolve
Is the polar head or non-polar tail hydrophobic?
How is a phospholipid bilayer constructed?
The polar heads of a molecule face the water outside and inside the cell, while the non-polar tails face and interact with each other.
Describe the type of bond and shape of a water molecule?
-It is a polar covalent bond, with the 2 partial positively charged hydrogen atoms in a 'V' off the end of a partially negatively charged oxygen atom at the other end.
What is a hydrogen bond?
The attraction between an already bonded positively charged hydrogen atom and another negatively charged molecule, it is an intermolecular bond about 1/10 the strength of a covalent bond.
What is the difference between an intramolecular and an intermolecular bond?
Intramolecular: Bond within same molecule
Intermolecular: Bond between two separate atoms
What are 2 thermal properties of water?
1) High heat capacity i.e. needs a lot of heat energy to change temperature by 1 degree
2) High heat of vaporization i.e. needs a lot of heat energy to evaporate 1 gram of liquid
How are these 2 thermal properties useful in our survival?
1) A high heat capacity aids in homeostasis, as our body only has a small window that it can function in>
2) A high heat vaporization means when we perspire, the evaporating water absorbs about 2 kilojules of heat energy, thus cooling the body.