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.