Biochemistry – Unit 2

Physical Vs Chemical Change

Organic Chemistry

Organic = it contains carbon, or was once alive.

Organic Chemistry

Carbon can covalently bond with up to four other atoms.

Organic Compounds

1. Carbohydrates2. Lipids3. Proteins4. Nucleic Acids

Carbohydrates

Contain: Carbon / Hydrogen & OxygenProvide energy for the organismRatio: 1:2:1Monosaccharides = 1 sugarDisaccharides = 2 sugarsPolysaccharides = 3 sugars

Monosaccharides = C6H12O6

= “one sugar”GlucoseFructoseGalactose

These are ISOMERS = same chemical formula different structural formula

Monosaccharides

Disaccharides

Polysaccharides

How do monosaccharides make a disaccharide or polysaccharide?It’s “dehydrated” – a WATER molecule is removed – often called condensation or dehydration synthesis.

Polysaccharides

HydrolysisIn a reaction opposite to dehydration, a water molecule can be added to split a polymer in two: HydrolysisThink of chewing a Saltine cracker

Animations: Campbell

LIPIDS

LipidsLipids are molecules that have a Glycerol molecule…Connected to three fatty acid chains hydrocarbon chains. Lipids are NON polar.

LIPIDSGlycerol Three Fatty Acids

Saturated vs. Unsaturated Fat

Proteins

Proteins are building blocks of structures called amino acids. A peptide bond forms between amino acids by dehydration synthesis.They contain: C, H, O & N (Nitrogen)

Nucleic Acids: DNA & RNA (the fourth type of Organic Compound)

Most cells contain DNA /RNANucleic Acids are made up of long chain of nucleotidesNucleotides are made up of three parts: Sugar Base Phosphate group

RNA molecule

DNA Vs RNA

DNA: Remains in the nucleus Has four bases (A,C,T,G) Double Stranded

RNA: Can go from nucleus to cytoplasm Has four bases (A,C,U,G) Single Stranded

Enzymes

ATP = Adenosine triphosphate

A high energy molecule“ENERGY CURRENCY” of cellsWhen food is broken down – it is converted to ENERGY = ATP

pH – measures the concentration of H+ ions in solution

Acid Vs Base

Acid – pH value of: 0 - 6.9 (red litmus)

Base – pH value of: 7.1 – 14 (blue litmus)

Neutral = 7Buffer: a substance that resists changes in pH when an acid or base is added

Protein Structure

LevelPrimary

Secondary

Tertiary

Quaternary

DescriptionThe amino acid

sequenceHelices and Sheets

Disulfide bridges

Multiple polypeptides connect

Animations

Carbs: http://www.youtube.com/watch?v=QckfYvIlVu4 Lipids: http://www.youtube.com/watch?v=3xF_LK9pnL0&feature=channel Proteins:http://www.youtube.com/watch?v=w-ctkPUUpUc&feature=relmfu