Biological Mpleculws 1 Flashcards
Name some monosaccarides
Glucose Galactose and fructose
How does the structure of glucose relate to its function
Small and water soluble so easily transported I’m the bloodstream
Complementary shape to the antip for co transport for absorption in the gut
Complementary shape to enzymes for glycolysis
How is the strcytyre of glycogen suitable for its function
Long chain of alpha glucose molecules joined by 1,4 glucoside bonds. It is an energy store in animals. Due to having many side branches it can be broken down to release glucose. It Is also large but compact due to the coiling nature of its polymer chain
Why light an animal not be able to digest cellulose
Due to it not containing the enzymes to digest the 1,4 glucoside bonds between beta glucose molecules. It may he hard to hydrole because it is a polysaccaride
Why are lipids good at storing energy
Because it is insoluble and non polar so it does not interfere with any water based reactions taking place in the cytoplasm
What is the function of phospholipid bilayer
Forms a partially permeable membrane. It only allows certain substances to pass through for example oxygen and carbon dioxide
Keeps the membrane fluid but stable
The tail prevents unwanted polar ions and molecules to pass in the cell and prevents water soluble molecules like amino acid and glucose from entering
Only small non polr molecules can enter
What affects the fluidity of the cell membrane
Length of the fatty acid chain: the shorter the chain
Saturation of fatty acid: more unsaturated the more fluid due to it creating a kink which makes them fit more loosely
Cholestrol
How does a polypeptide form
Chains of amino acid linked together by condensation recations. This occurs as a part of protein synthesis called translation. During condensation, a peptide bond forms between he amine groups nd the carboxylic group of another amino acid and water is produced
How do proteins form?
Many amino acids joined together by peptide bonds
Structure of proteins 1-4
Primary
Secondary
Tertiary
Quarternery
Primary
Sequence of amino acids within a polypeptide chain joined together by peptide bonds
Secondary
Folding of the polypeptide chain into alphabheoices or beta pleated held together by hydrogen bonds and due to formation of hydrogen bonds
Tertairy
The 3 dimensional folding of the secondary structure into a complex shape determined by the type of bondin
H
I
D
Determined by the folding of an alpha or beta pleated sheet folding caused by interactions between r groups of amino acids
Why do alpha helices and beta pleated form
Due to structure of amino acids
Quaternary strcuture
3D arrangement of more than one polypeptide
Fibrous protein
Include collagen
Long parallel polypeptide
Very little teriaru or quaternary structure mainly secondary
Occasional cross linkages which form microfibrils for strength
Insoluble
Structural purposes
Globular
U
Globular proteins
Complex teriary quaternary structure Form colloids in water Includes haemoglobin Spherical in shape Hydrophobic R groups on the inside Hydrophilic r groups on the outside Soluble in water anything soluble makes bond with the water Specific shape to carry out specific functions
Role of globular proteins
Transport
Hormones
Enzymes
Metabolic roles
Holding molecules in position in cytoplasm
Immune system producing antibodies which are globular proteins
Maintain strcutyr of cytoplams
How does the structure of collagen relate to their function
Fibrous proteins that give strength to bones and tendons and ligaments
Structural protein
Strong due to fibres having high tensile strength due to structure of collagen
3 polypeptide chains of repeating glyceine, proline and hydroxyproline.
3 alpha chains arranged in triple helix held together by hydrogen bonds
Glycerine held close together to form triple helix
Covalent bonds forming cross links holding collagen molecules together to form fibrils
Hydrogen bonds= withstand pulling forces without stretching or breaking
Stable protein due to Hugh number of proline and hydroxyproline amino acids resulting in more stability as their R groups repel each other.
How does the structure of hamoglobin relate to their function
4 polypeptide chains held together by disulfide bonds each carrying a haem group which can bind to oxygen
Large molecule
Iron containing haem group
It is the iron that enable the haemoglobin haemoglobin bind to oxygen and polypeptide chains that determine how easy it is to bind or release oxygen
G
G
Compare collagen with heamoglobin
Collagen Triple helix Long Fibrous Haemoglobin 4 2 alpha 2 globin trands Spherical Globular
