Presentation on theme: "Biochemistry to Cells Chapters 2 and 3. Anatomy is Structure, Physiology is function Anatomy – Study of internal and external structure – i.e. structure."— Presentation transcript:
Biochemistry to Cells Chapters 2 and 3
Anatomy is Structure, Physiology is function Anatomy – Study of internal and external structure – i.e. structure of heart and blood flow Physiology – Study of how organisms perform specific functions – i.e. how does the heart pump blood
Levels of Organization in the Body.
Inorganic versus Organic Compounds Inorganic Small molecules that generally do not contain carbon and hydrogen atoms. Organic Molecules composed of carbon and hydrogen molecules Larger and more complex than inorganic molecules
Carbohydrates Sugars and Starches Contain carbon, hydrogen and oxygen in a 1:2:1 ratio Main source of energy for body Monosaccharides – Glucose, fructose, galactose Disaccharides – Lactose, maltose, sucrose Polysaccharides – Glycogen, starch, cellulose Monosaccharides – building blocks for all sugars
From Monomers to Polymers
Dehydration Synthesis Remove water to build large molecules from smaller ones i.e. making proteins from amino acids Hydrolysis Split water to break down large molecules into small i.e. digestive tract
Lipids Fats, oils and waxes Contain large amounts of carbon and hydrogen in a 1:2 ratio, but very little oxygen. Insoluble in water (hydophobic), makes a great barrier. Energy reserves, insulates and cushions organs Composed of fatty acid chains and glycerol
Saturated No double bonds, all carbon atoms are saturated with hydrogen Animal fats, are solid at room temperature Large amounts in your diet increases the risk of heart disease Unsaturated Contain at least one double bond Most Plant oils, liquid at room temperature Triglycerides are the most common fats in body.
Phospholipids How is structure related to function? Consists of a glycerol and two fatty acid chains linked to a phosphate group (PO 4 ) The phosphate group is attracted to water (hydrophilic), Why? The fatty acid chains are hydrophobic. Make up all cell membranes
Cell membrane composed of phospholipids and proteins.
Proteins Most abundant organic compounds in the body Composed of amino acids, 20 different amino acids Structure of an amino acid – Amino group – H – Carboxyl group – R (remaining), varies from one amino acid to another Peptide bond joins two amino acids together
Proteins The structure of the R group makes the amino acids different from each other. The R groups between the different amino acids help create the proteins shape. Folds and bonds form creating distinct protein shapes
Shape Determines Function Structure of a protein is determined by sequence of amino acids Proteins are made at the _________ and sent to the ____________ to be packaged into their specific shape. Small differences can have large effects… mutations
Formation of Proteins
Protein Function Support: provide structure to cells and organs Movement: contractile proteins in muscles Transport: carrier protein found in cell membranes Metabolic Regulation: Enzymes speed up chemical reactions Coordination and Control: Protein hormones influence the chemical reactions in cells Defense: keratin in the skin, antibodies, clotting proteins
Enzyme Function Enzymes are Proteins Speed up chemical reactions in a cell by reducing the activation energy needed to start the reaction. Enzymes control all life processes. Enzyme shape determines function. Shape of proteins can be altered by pH, temperature, or ion composition
Enzyme Function Substrate – reactant that enzyme affects Active site – region on enzyme that substrate attaches to. – Lock and Key arrangement Each enzyme catalyzes only one type of reaction (specificity)
Nucleic Acids: DNA and RNA Basic building block is a nucleotide. Structural similarities: Structural differences:
Nucleus – Composed of Chromatin (DNA)
Chromatin DNA wrapped around 8 histone proteins, creates a subunit called a nucleosome. How tightly packed the DNA is around the nucleosome and its tails helps determine gene expression
Two Types of Chromatin EuchromatinHeterochromatin
Transcription – rewriting of DNA into RNA; controlled by RNA polymerase Translation- changing the message of nucleic acids into an amino acid chain (protein) Which nucleic acid carries the code for the protein?
Translation- occurs in the ribosome Role of mRNA: tRNA: rRNA: Codons: Anticodons:
How is gene expression controlled in Eukaryotic cells? Heterochromatin Epigenetics – study of changes in gene expression caused by histone modification and DNA methylation other than changes in the DNA sequence (mutations) Regulates gene expression w/o changing the DNA Changes have been shown to be heritable. RNAi (RNA interference) Double stranded RNA molecules that inhibit gene expression (What?) Small interfering RNAs (siRNA) attach to mRNA The mRNA is then cut up by a number of enzymes (agronaute and dicer). Why does this affect gene transcription? What advantage doe s this give our cells?
Cells are composed of organic compounds.
ATP – energy currency for cell ATP → ADP + P Energy is released
Mitochondria – Powerhouse of cell. How does form relate to function?