Lecture 1 - Key Molecules of Life PDF

Lecture 1 – Key molecules of life Prokaryote cells do not have nucleus such as bacteria and archaea (have features like human). Eukaryote cells have nucleus such as Plant (cell wall and chloroplasts), Fungus (cell wall and no chloroplasts, and animal (no cell wall and no chlo...

Lecture 1 – Key molecules of life Prokaryote cells do not have nucleus such as bacteria and archaea (have features like human). Eukaryote cells have nucleus such as Plant (cell wall and chloroplasts), Fungus (cell wall and no chloroplasts, and animal (no cell wall and no chloroplasts). Links between Molecules -> cells -> organism Phenotype – refers to an individual observable trait such as height, eye colour and blood type. Genotype – refers to the genetic makeup of an organism. Change is shape of haemoglobin leads to Sickel cell anaemia. Phospholipase is an enzyme  Small molecules make larger molecules  Glucose is stored in the liver. Glucose molecules have covalent bonds. If you tip glucose in solution form (through linear form), then it will be ~36% a- glucose and ~64% B-glucose.  The hydrophilic head interacts with water. The hydrophobic tail doesn’t interact with water. This allows membrane to form Where the fatty acid tails are in contact with each other and the hydrophilic bits act as two water absorbing layers, one on each side of the membrane. Membrane are not stiff, they move.  Membrane lipids are an example of phospholipids which have alcohol attached to phosphate, glycerol, and 2 fatty acids. Fatty acids can be saturated or unsaturated or one of them each. There is estrogen and progesterone but they both are decorated with different chemical elements. That different decoration alters the function and timing of their function. Estrogen and progesterone, though chemically different, bind to cell receptors and trigger changes in metabolism and physiology, influencing the menstrual cycle. Initially, their levels rise, preparing for ovulation, and then drop just before it occurs. After ovulation, estrogen decreases, triggering a rise in progesterone, preparing the body for the post-ovulation phase. These hormones regulate the production of eggs.  There's the single hydrogen. And if we have hydroxyl on one chain a one carbon chain then the amino acid is serine. Hydroxyl is soluble. So, serine is a water loving. It can interact with water. The only reason valium is soluble is because of the amino group and the carboxyl group. But the group avoids water. Its water fearing is insoluble. It's therefore hydrophobic.  The chemical ends of this necklace of amino acids differ. At the one end they have the amino group, at the other end they have the carboxyl group. So we called this N and C terminus. Polarity means directionally. But proteins have polarity. Directionality of information. And the information in a protein is read from N to C and terminus to see to this. That's the only direction that makes biological sense.  The structure of a nucleotide is made from a sugar attached to phosphate. Or a sugar attached to any one of four nitrogenous bases G, A, T and C. When phosphate attached to sugar and they both attach to base, we make nucleotide, and the nucleotide are then polymerised to make nucleic acids. Nucleic acids are read from 5’ to 3’. The information we decode from DNA to RNA is always in one direction.