Quiz – Page 381. Give 3 examples of a structural protein.

2. What class of protein in ferretin?

3. What does kinesin do?

4. What protein carries iron?

5. What class of protein is rhodopsin.

collagen, elastin, tubulin, keratin,a ctin

storage

it interacts with microtubules to move organelles

transferrin

receptor

Proteins Homework due today!

Lesson 8– Catalysis

Nucleic AcidsOn your desks draw out the structure of a nucleic acid as you remember it.

Nucleotide StructureAll nucleotides are made up of a pentose sugar, a phosphate group and a variable nitrogenous base.

Purines and PyrimidinesThere are 2 types of nitrogenous bases – purines (double ring structures) and pyrimidines (single ring structures).

UracilUracil has one ring so it is a….

pyrimidineIn fact it is structurally VERY similar to Thymine.

Nucleotide Structure Up Close

The Phosphodiester Bond

A bond forms between the phosphate group (C5) of one nucleotide and the hydroxyl group (C3) on the sugar of another.

The nucleotide monomers are joined by a dehyration synthesis reaction.

Phosphodiester bond

Base PairingOn your desks write how the bases pair up. Indicate which are purines and which are pyrimidines.

Purines always pair with pyrimidines. They are held together by hydrogen bonds.

3 bonds between C andG and 2 bonds between T and A (or U and A).

The Double HelixThe 2 strands of the double helix are in an anti-parallel arrangement.

3’ and 5’3’ is read “three prime” and refers to the third carbon on the sugar. Five prime refers to the 5th.

Antiparallel Arrangement showing 3’ and 5’

Double Helix (again)Features of the DNS double helix:

1. One complete turn has a length of 3.4 nm.

2. The diameter of the molecule is 2.0 nm.

3. There is a major groove and a minor groove.

4. The helix is described as right handed.

RNA vs DNAList ways that DNA and RNA differ.

Polymerase Enzymes

DNA LigaseWhen describing proteins we can identify motifs and domains in the protein.

Motif – a particular form of secondary structure. An examples include βαβmotif or βbarrel.

Domains – regions of a polypeptide chain that fold independently to give distinct regions with potentially different roles

Your Task- Nucleic Acids1. Past Paper QuestionsYou will need to access these in the department. Please DO NOT TAKE past papers home – we have limited numbers.

2002 MC Q52004 MC Q12

2006 Section B Q12008 MC 52009 Q6

2. Complete Scholar activities on nucleic acids.3. Read and make notes on pages 39-42.4. Make sure your glossary is up to date.

DUE Monday(November 26th)