Biological Molecules Flashcards
Key properties of water
. Liquid at room temp . Higher density in liquid state compared to solid . Upthrust Force . Cohesive Properties . Adhesive Properties . Acts as a coolant . Polar molecule
What is a carbohydrates
Are a molecular compound which provide energy (short term) for functions such as regulation of blood glucose
What is the structural variation in alpha and beta glucose
In the alpha and beta glucose the OH (Hydroxyl group) group of carbon 1 is in opposite positions (alpha= above the plane, beta= below the plane)
How is a disaccharides formed?
. They form when two monosaccharide units join forming a glycosidic bond (condensation reaction)
. This can be from two of the same monosaccharides or two different ones
. For example glucose + fructose gives sucrose (and water)
What is a polysaccharide
. Is a molecule made up of multiple monosaccharides
. Is a slow release energy
. Examples would be cellulose, starch and glycogen
Properties of Starch
- More soluble than glucose molecules
- Has no taste or Oder
- Energy store in plants
- Example of starch would be Amylose (1,4 bond) and amylopectin (1,4 bond and glycosidic)
Properties of cellulose
- Strong and insoluble
- Is a straight molecule (not branched)
- Make hydrogen bonds with each other
Properties of glycogen
- Easy molecule for storage
- Further Glucose molecules able to be added or removed
- Insoluble and compact
- Found in mainly liver and muscle cells
Definition of a polypeptide
A polypeptide is a chain of amino acids. Proteins are made up of one of more polypeptide chain
Characteristics of a Primary Protein Structure
. Straight chain of amino acids
. Particular amino acids in the chain influence how the polypeptide folds to give the final shape (Will determine function)
. Only bonds involved in the primary structure of a protein are peptide bonds
Characteristics of Secondary Structure(Alpha)
. Coil shape
. The oxygenw, hydrogen and nitrogen atoms of the basic, repeating structure of the amino acids interact
. Hydrogen bonds may form within the amino acid chain which pull it into a coil shape
. Hydrogen bonding every 4th amino acid
Characteristics of Secondary Structure (Beta)
. Sheet like structure joined by hydrogen bonds
. Pattern formed by the individual amino acid causes the structure to appear pleated
Characteristics of Tertiary Structure
. Folding of protein into its final shape
. Coiling or folding brings R-groups closer so they can interact and further coiling occurs
. Forms Hydrogen bonds, Ionic Bonds, Hydrophobic and Hydrophilic interactions and Disulphide bridges
. Looks like a backwards S
Characteristics of Quaternary Structure
. Made up of several polypeptide chains held together
. Same bonds as tertiary
. Forms a biologically active molecule
. Eg Haemoglobin
What is a phospholipid
. Are modified triglycerides
. Found in cytoplasm of each cell
. Negatively charged so soluble
. One fatty acid chain in a triglyceride molecule is replaced with a phosphate group to make a phospholipid
Saturated lipid
Only has C-C bonds
Found in animals fats and has a high MP
Eg lard
UnSaturated lipid
Contains C=C bonds in the chain
Found in plant oils and have Low MP
They have a low MP due to having weak intermolecular forces of attraction
Formation of a triglyceride
Glycerol + 3 Fatty Acids
What is a Fibrous Protein
. Formed from large insoluble molecules
. Limited range of amino structure (small R-groups)
. Has an organised structure (Repetition of primary structure)
. Examples would be Keratin, Elastin and Collagen
Globular Proteins
. Compact, water soluble and spherical
. Form when proteins fold into a tertiary structure (so amino acids are kept in an aqueous environment
. Solubility is important for many functions like regulation processes for life
. An example would be insulin
Conjugated Proteins
. Are globular proteins containing a non-protein component called a prosthetic group
. An example of this would be Haem group. Contains an Iron (II) ion Fe2+
. Catalase and Haemoglobin contain a haem group
. Examples would be Catalase and Haemoglobin
Keratin
. Present in hair and skin
. Contain large amount of sulphur (Reason burnt skin smells)
. Is a strong, inflexible and insoluble material (due to disulphide bond/bridges)
Elastin
. Fibrous protein in elastic fibres
. Present in wall of blood vessels and alveoli
. Is a quaternary protein made from stretch molecules
