Chapter 2 bio

• Nucleic acids

  Information molecules that encode instructions for the synthesis of proteins
• DNA


  The structure of DNA
• RNA


  The three main forms of RNA (mRNA, rRNA, and tRNA), and a comparison of their respective nucleotides
• Genetic code


  A universal triplet code that is degenerate and the steps in gene expression, including transcription, RNA processing in eukaryotic cells, and translation by ribosomes
• Gene


  The structure of genes: exons, introns, and promoter and operator regions
• Gene regulation


  The basic elements of gene regulation: prokaryotic trp operon as a simplified example of a regulatory process
• Amino acids


  The monomers of a polypeptide chain and the resultant hierarchical levels of structure that give rise to a functional protein
• Proteins


  A diverse group of molecules that collectively make an organism's proteome, including enzymes as catalysts in biochemical pathways
• Protein secretory pathway


  The role of rough endoplasmic reticulum, Golgi apparatus, and associated vesicles in the export of proteins from a cell
• Proteins


  • They are large complex structures which are crucial to the functioning and development of all living organisms, serving a variety of different functions
• Functions of proteins


  • Enzymes
  • Transport
  • Structural
  • Defence
  • Motor/contractile
  • Storage
  • Receptors
  • Hormones
• Enzyme


  Organic catalysts that speed up chemical reactions
• Enzymes


  • Catalase
  • Amylase
  • RNA polymerase
• Transport proteins


  Typically embedded in membranes, controlling the entry and exit of substances from a cell
• Transport proteins


  • Chloride channels
  • Glucose channels
  • Sodium-potassium pumps
• Structural proteins


  Support cell and tissue shape
• Structural proteins


  • Keratin
  • Elastin
  • Collagen
• Defence proteins


  Involved in the immune system by recognising and destroying pathogens
• Defence proteins


  • Antibodies (immunoglobulins)
  • Complement proteins
• Motor/contractile proteins


  Involved in the contraction and movement of muscles, the movement of internal cell contents around the cytoplasm, and the movement of cilia and flagella
• Motor/contractile proteins


  • Myosin and actin
  • Kinesin
• Storage proteins


  Act as reserves for metal ions and other molecules throughout organisms
• Storage proteins


  • Ferritin
  • Casein
• Receptor proteins


  Receive signals from the environment
• Receptor proteins


  • Acetylcholine receptors
  • Hormone receptors
• Hormone proteins


  Peptide hormones that are chemical messengers used to communicate and induce changes in cells
• Hormone proteins


  • Insulin
  • Adrenaline
• Amino acid


  The monomers of a polypeptide chain, consisting of a central carbon atom, a carboxyl group, an amino group, an R-group, and a hydrogen atom
• Polypeptide


  A long chain of amino acids
• Protein


  The polymers of amino acids
• Hydrophobic


  Having a tendency to repel and be insoluble in water
• Hydrophilic


  Having a tendency to be attracted to and dissolve in water
• Monomer


  A molecule that is the smallest building block of a polymer
• Polymer


  A large molecule that is made up of small, repeated monomer subunits
• Condensation reaction


  A reaction where two monomers join to form a larger molecule, producing water as a by-product
• Peptide bond


  The chemical bond linking two amino acids
• Primary structure


  The sequence (or order) of amino acids in a polypeptide chain
• Secondary structure


  The arrangement of the polypeptide chain into alpha-helices, beta-pleated sheets, or random coils
• Tertiary structure


  The functional 3D shape of the protein
• Quaternary structure


  The bonding of multiple polypeptide chains together