Carbohydrates
What are condensation reactions?
Monosaccharides are formed into disaccharides and polysaccharides by glycosidic bonds in condensation reaction.
Name the chemical bonds that link the amino acids in the molecule.
Peptide (bonds)
What bonds form between lipids?
Ester Bonds
What are the three components of DNA / nucleotide
Phosphate, deoxyribose (sugar) and a nitrogen base
What're the two isomers of glucose?
Alpha glucose (a-glucose) and Beta glucose (β-glucose)
Test for Protein
Add Biuret reagent to the sample and the colour should change to lilac.
What is Hydrophobic and Hydrophilic?
Hydrophobic- Fatty acid chain have no charge so they're not attracted to dipoles of water molecules.
Hydrophilic- Phosphate group has an electrical charge and are attracted to water molecules.
What is DNA?
A DNA molecule is a double helix composed of two polynucleotides joined together by a hydrogen bonds between complementary bases whereas RNA is single-stranded.
Properties of Glycogen?
Formed by many molecules of alpha glucose joined by 1,4 glycosidic bonds. It has a large number of branches meaning the molecules can be hydrolyzed and the energy can be released quickly. It is large and compact (takes less space and is good ti store large amount of energy). Glycogen are usually the main energy storage molecules in animals.
Properties of Fiborous proteins
-Long parallel polypeptides
-Very little tertiary/quaternary structure
-Occasional cross-linkages which form micro-fibres for tensile strength
-Insoluble
-Used for structural purposes
Difference between saturated and Unsaturated fatty acids?
-Fatty acids where there are no double bonds between carbon atoms are called saturated fatty acids.
-Fatty acids where there is at least one carbon-carbon double bond present is called unsaturated fatty acids.
What're codon and anti-codon
codon- Three nucleotides or nitrogen bases.
anticodon- three nitrogen bases on a tRNA molecule.
What are the properties of amylose and Amylopectin?
Amylose- Unbranched chain of glucose, joined by 1.4 glycosidic bonds. It is coiled so it has a very compact structure and so good for storage of energy.
Amylopectin- Branched chain of glucose, joined by 1,6 bonds, Contains many side branches so it gets digested rapidly by enzymes so there is a quick release of energy.
Explain how a change in the primary structure of a globular protein may result in a different three dimensional structure?
The sequence of the amino acids changes and the bonds are formed in different places which changes the tertiary structure so it folds in a different way.
What are Phospholipids?
-Contains two fatty acids, glycerol and a phosphate group. Phosphate heads are Hydrophilic and tails are hydrophobic.
-The phospholipids forms a bilayer in the cell membranes.
Process of transcription?
The information in DNA is transferred to the mRNA.
- Enzymes unzip the molecule of DNA.
-Free RNA nucleotides form base pairs with their complimentary nucleotides of DNA.
-The mRNA strand leaves the nucleus.
Properties of Cellulose.
Cellulose is a structural polysaccharide found in cell walls of plant cells. It contains beta glucose rather than alpha, has long unbranched chains that are joined by 1,4 glycosidic bonds. It provides structural support to the plant cell and prevents the cell from taking up too much water.
How can an increase in temperature van lead to a non-functining protein?
An increase in the temperature can cause the bonds (hydrogen or ionic) which holds the tertiary structure together to break. The shape of the protein won't be maintained and will be disfigured.
Properties of lipids?
-They're waterproof because the fatty tail is hydrophobic.
-Very compact, better gram for gram, energy release as more Carbon oxygen bonds ate hydrolysed.
-Non polar and Insoluble in water (good for storage, doesn't interfere water based reactions in cytoplasm)
-Thermal Insulation as lipids produces heat slowly. (Adipose tissue underneath skin).
Process of translation?
Converting the information of mRNA into a sequence of amino acids in proteins.
- A ribosome attaches to the mRNA strand. A tRNA anticodon matches with the mRNA codon.
-The ribosome then slides over one codon on the mRNA.
-The new tRNA molecule carrying another amino acid pairs with the second mRNA codon.
-The amino acids are joined by a peptide bond.
-A chain of amino acids is formed until a stop codon is reached.
-The amino acids become a protein when released from the ribosome. The chain twist up to make a protein.