Class Notes (835,340)
Canada (509,114)
Biology (641)
BIOL 2020 (121)

Section 1.docx

5 Pages
Unlock Document

BIOL 2020
Patrice Cote

Section 1 December-08-11 10:46 AM Four types of biological molecules  Carbohydrates (sugars) o Monosaccharides  (CH2O)n  A single monomer o Disaccharides  Ex. Sucrose  Two monomers o Oligosaccharides  A small chain of 3-10 monomers covalently attached to lipids and proteins  Can attach to lipids, and proteins  Are found near the surface of the cell  They're like a cell's ID tag o Polysaccharides  Composed of many monomers  Many different polysaccharides can be formed with the same sugars, but using different bonds  Proteins  Nucleic acids  Carbs, proteins and nucleic acids start as monomers and combine into polymers  Lipids o Soluble in certain organic solvents o Not soluble in water o Fats  Composed of three fatty acid tails bound to a glycerol moiety via ester bonds  Used mainly as energy stores  Stores in cells called adipocytes  Fatty Acids  Are amphipathic  Hydrocarbon chain  Hydrophobic  Carboxyl group (-COOH)  Hydrophilic  Kinks in fatty acid tails are C=O  Cis-fatty acid  Kinked unsaturated fatty acid  Liquid at room temperatire  Trans-fatty acid  Unsaturated, but not kinked C=C bond  o Steroids  Cholesterol is the best known steroid  Found in membranes  Sits between fatty acid tails  Makes the membrane more rigid  Is amphipathic because of its OH group  The rest of the cholesterol is hydrophobic  This causes molecules of cholesterol to clump together o Phospholipids  Composed of glycerol moiety with two fatty acid tails, a phosphate group, bound to a polar head group  Fatty acid tails hydrophobic, the rest is hydrophilic  Are the basic building blocks of cells Building blocks of macromolecules  Monosaccharides --> Polysaccharides  Fatty acids --> Lipids  Amino acids --> Proteins  Nucleotides --> Nucleic Acids Amino acids  Alpha carbon bound to: o Carboxyl group o Amino group o R group (side chain) o Hydrogen  Types of R groups o Polar charged  Hydrophilic, acts as acid or base, full charge (+ or -), form ionic bonds and tend to be involved in chemical reactions o Polar uncharged  Hydrophilic, partial charge (+ or -), can participate in chemical reactions, form H bonds and associate with water  Usually faces outside of protein o Nonpolar  Hydrophobic, forms the inner core of soluble proteins. Associates with lipid bilayer in membranes  Points towards lipids, or inner core of protein o Unique properties  Glycine  Single H, fits in hydrophilic or hydrophobic environment, at sites of close contact between two polypeptides  Makes polypeptide chain flexible  Cysteine  Can form a covalent link with another cysteine to form a disulfide link  Proline  Has a cyclic structure; bonds from alpha carbon to the N group on an amino acid  Produces a kink in the chain  Will eventually disrupt the secondary structure of a protein  Join via peptide bonds o H of Amino group binds to OH of carboxyl group
More Less

Related notes for BIOL 2020

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.