Steroid Structure

Protein Structure and Function

Proteins Polymers made of amino acid monomers Amino acids:

Central carbon bonded to carboxyl Amino group Hydrogen Atom R group

Peptide Bonds

Peptide Bond Link amino acids dehydration synthesis

Protein function depends

On # and order of amino

acids

Four levels of protein structure Primary: sequence of amino acids

Secondary: refers to one of two 3D structures that result from H bonding Alpha helix “spring” Beta pleated sheet “accordion”

Tertiary: Complex globular shape Result of interactions between R groups Hydrophobic interactions Van der Waals Disulfide bridges

Quaternary: two or more polypeptides forming one large protein.

Levels of Protein Structure

Shape Dictates Function Improper protein folding can lead to a variety of

diseases Cancer Sickle-cell disease: abnormal hemoglobin Prions Alhezimers disease

Chaperonins: assist in proper folding Provide proper folding environment

Denaturation Protein looses shape and or function

Heat pH Salt concentrations

Chaperonin

Alzheimer's disease Beta-amyloid is a fragment from a larger

protein called amyloid precursor protein APP.

Cut by enzymes

Leads to plaque formation

Plaques disrupt calcium concentration, accumulate on mitochondria, induce apoptosis

Magnetic Resonance Imaging Research from Drs. Yang and Meadowcroft at

the Penn State Hershey Med Center, Center for Nuclear Magnetic Resonance Research.

Nucleic Acids

Store and transmit hereditary information DNA (deoxyribonucleic acid) RNA (ribonucleic acid) Both have monomer nucleotides

Nucleotides 3 parts Nitrogenous Base: adenine, thymine, cytosine,

guanine, uralic Pentose: 5 carbon sugar Phosphate:

Nucleic Acid Structure

DNA & RNA DNA is the molecule of heredity

Double stranded helix Composed of

Adenine Thymine Cytosine Guanine G bonds C A bonds T

RNA Single Stranded Composed of

Adenine Cytosine Guanine Uracil

Monomer & Polymer Summary Table

Macromolecule/Polymer

Monomers/Components

Examples Functions

Carbohydrates Monosaccharides Sugar, starch, glycogen, cellulose

Energy, energy storage, structural

Lipids Fatty Acids and Glycerol

Fats, Oils Energy source, insulation

Proteins Amino Acids Hmoglobin, Ppsin

Enzymes, movemnent

Nucleic Acids Nucleotides DNA, RNA Heredity; code for amino acid sequence

Concept Check

1. Which two functional groups are always found in amino acids?

2. Describe why phospholipids are important components of cell membranes, based on their structure and properties

3. Hydrolysis is involved in 1. A. Formation of starch2. B. hydrogen bond formation between nucleic acids3. C. Peptide bond formation of proteins4. They hydrophilic interactions of lipids5. The digestion of maltose to glucose

4. Compare and Contrast DNA vs RNA

Concept Check Responses

1. Carboxyl (the acid part), amino (the amino part)

2. Polar head, apolar tail, bilayer, fluid, semipermeable membrane

3. E is correct, hydrolysis, hydro-water, lysis-splits. Look for a large polymer split to monomer.

4. DNA double stranded RNA Single stranded, DNA Thymidine, RNA Uracil, DNA deoxyribose, RNA ribose