Download - Chapter2 biochemistry
Biochemistry
Chemistry Comes to Life
Energy Types:How do these relate to living systems?
• Chemical energy
• Electrical energy
• Mechanical energy
• Radiant energy
How do these relate to the ideas of potential and kinetic energy?
Chemical bonds
• Ionic
• Covalent
• Hydrogen bonds
Ionic bonds• Involve electron transfer from one atom to
another.• Common in salts, electrolytes• Ions are necessary for many body
functions
Covalent Bonds• Shared electrons
• Stable compounds
• Polar covalent bonds in water have biochemical significance
Hydrogen Bonds
• Weak bonds• Involved in water tension• Create intramolecular bonds which bind parts of
the same molecule together• Significant in the shape of proteins, DNA, and enzyme function
Patterns of Chemical Reactions
Synthesis Reaction
Examples: amino acids joined to make proteins, simple sugars joined on to polysaccharides.
Protein Synthesis link
Patterns of Chemical Reactions
Decomposition reactions Example: glycogen broken down to
glucose molecules http://student.ccbcmd.edu/~gkaiser/biotutorials/energy/adpan.html
Patterns of Chemical Reactions
Exchange or displacement reactions
Example: Hemoglobin picks up Oxygen and unloads Carbon Dioxide.
Significant inorganic molecules
• Water
• Salts
• Acids and Bases
Biological significance of water
• High Heat Capacity– Prevents sudden changes in body temp.
• Polarity and Solvent Properties– Salts, O2, CO2, dissolved in blood; lubricant
molecules
• Chemical Reactivity– Reactant in digestion; hydrolysis
• Cushioning properties– CSF, amniotic fluid
Polarity and Solvent Properties
Organic Macromolecules
• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids
• ATP
Biological Macromolecules
Carbohydrates
• C, H, O
• H:O::2:1
• 3 Types– Monosaccharide– Disaccharides– Polysaccharides
• Starches in plants• Glycogen in animals
Lipids
• Lipids are hydrophobic –”water fearing”
• Do NOT mix with water
• Includes fats, waxes, steroids, & oils
•Function
Fats store energy, help to insulate the body, and cushion and protect organs
Lipids:Triglycerides
• Triglycerides (neutral fats): Glycerol + 3 fatty acid chains– Saturated: in animals, solid at room T, called fats– Unsaturated: in plants, liquid at room T, called oils– Transfats: man-made unsaturated, solid fat.
Lipids: Phospholipids
Cell Membrane up close and personal
Lipids: steroids
• Flat, four-ring shape
• From cholesterol and sex hormones.
Proteins
• Proteins are polymers made of monomers called amino acids
• All proteins are made of 20 different amino acids linked in different orders
• Proteins are used to build cells, act as hormones & enzymes, and do much of the work in a cell
Proteins
• C,H,O,N and sometimes S• Made up of chains of amino acids• Structural proteins: muscle, keratin, collagen; make up
50% of organic matter• Functional proteins
– Antibodies– Hormones– Transport protein: hemoglobin– Enzymes: biological catalysts– http://www.lewport.wnyric.org/jwanamaker/animations
/Enzyme%20activity.html
Nucleic Acids
• Store hereditary information• Contain information for making all the
body’s proteins
Two types exist --- DNA & RNA
Nucleic Acids:
DNA: Deoxyribonucleic Acid
Double Helix
•is the nucleic acid whose nucleotide sequence stores the genetic code for its own replication and for the sequence of
amino acids in proteins.
RNA: Ribonucleic Acid
Single Strand
• is a single-stranded nucleic acid that translates the genetic code of DNA into
the amino acid sequence of proteins.
Macromolecules
Macromolecules
ATP
Adenosine Triphosphate
ATP-energy molecule formed from breakdown of glucose.
ATP1. ATP (adenosine triphosphate) is a nucleotide
of adenosine composed of ribose and adenine. 2. Derives its name from three phosphates
attached to the five-carbon portion of the molecule.
3. ATP is a high-energy molecule because the last two unstable phosphate bonds are easily broken.
4. Usually in cells, a terminal phosphate bond is hydrolyzed, leaving ADP (adenosine diphosphate).
5. ATP is used in cells to supply energy for energy-requiring processes (e.g., synthetic reactions); whenever a cell carries out an activity or builds molecules, it "spends" ATP.