GENE AND GENOME: a gene is a sequence of bases on a DNA molecule coding for a sequence of amino acids in a polypeptide chain. Together all genes in an individual are known as the genome. DNA is a chain of nucleotides: DNA is one type of nucleic acid, called...
CF PROBLEMS: • CF is caused by a faulty transport protein in the surface membranes of epithelial cells • CF creates a sticky mucus layer that lines the tubes and ducts in the gas exchange, digestive and reproductive systems. • The sticky mucus increases the chances of...
Enzymes are globular proteins that act and biological catalysts (They speed up chemical reactions). There is a depression on the surface of the enzyme molecule called the active site. LOCK AND KEY THEORY: • a molecule with a complimentary shape can fit into the active...
FEATURES OF A GOOD GAS EXCHANGE SURFACE: • large surface area for the alveoli • numerous capillaries around the alveoli • thin walls of the alveoli and capillaries meaning a short distance between the alveolar air and the blood in the capillaries THE RATE OF DIFFUSION...
THE CELL SURFACE MEMBRANE CONSISTS OF: • Phospholipid bilayer (all the molecules are arranged so that the hydrophobic tails are inside the bilayer) • proteins • cholesterol • glycoproteins (protein molecules with polysaccharides attached) • glycolipids (lipid...
DIFFUSION: • High to low concentration until equilibrium reached • hydrophobic (lipid - soluble) or small uncharged molecules • through phospholipid bilayer • passive, no energy required FACILITATED DIFFUSION: • high to low concentration until equilibrium reached •...
Protein structure is key in protein function: Amino acids consist of an amine group, a carboxylic acid group, Primary structure - Two amino acids join in a condensation reaction to form a dipeptide (this can be more than two amino acids in length and they are joined...