Semester 2, Day 6

DNA, RNA, Proteins, and Semiconservative Replication

Agenda Study for Quiz Turn in Homework Quiz on Cells Lecture on DNA, RNA, Proteins, and

Semiconservative replication

Study Prokaryotic Bacteria Cell Eukaryotic Animal Cell Eukaryotic Plant Cell You should be able to label all organelles in

any type of cell You should be able to tell me the function of

each organelle in a cell

Homework Due Annotation: Sections 6.1, 6.2, 6.4, 6.5, 6.6 Concept Checks for each Section Chapter 6 Review

#1, 2, 4-10, 14-17, 19

DNA, RNA, and Proteins Recall: Nucleic Acids (DNA, RNA) are

macromolecules made up of linked monomers called nucleotides

Nucleotides - Sugars we’ll look at:

P

O

O

O-O-

Sugar

NitrogenousBase

Image Source: www.tutorhelpdesk.com

“un-oxygen”

difference of an oxygen

For DNA For RNA

DNA, RNA, and Proteins Nucleotides – Nitrogenous bases we’ll look at:

(DNA only)

(RNA only)

Image Source: www.cmlab.csie.ntu.edu.tw

DNA, RNA, and Proteins Chargaff’s Data:

% of Nitrogenous Bases in DNAOrganis

mA T G C

E. Coli 26.0 23.9 24.9 25.2Yeast 31.3 30.9 18.7 17.1Rat 28.6 28.4 21.4 21.5

Human 30.9 29.4 19.9 19.8

A T G CPurine with Pyrimidine

Image Source: bio1151.nicerweb.com

DNA, RNA, and Proteins X-Ray Diffraction:

Image Source: legacy.hopkinsville.kctcs.edu

Rosalind Franklin’s Photo 51= DOUBLE HELIX

Image Source: lebbeuswoods.wordpress.com

DNA, RNA, and Proteins Watson and Crick

Zoom-In

Cytosine & Guanine pair

w/ 3 hydrogen

bonds

Adenine & Thymine pair w/ 2 hydrogen

bonds

2 outside strands of alternating

deoxyribose sugars & phosphates

Image Source: academic.brooklyn.cuny.edu

DNA, RNA, and Proteins Why is DNA a double helix?

Image Source: whitni13.blogspot.com

Phosphates & sugars

are hydrophilic

( H2O)

Water can

enter here

Nitrogenous bases are hydrophobic ( H2O)

Space

Space

Space

Twisting shape minimizes

where water can get in

Antiparallel strands aid in creating the double helix

DNA, RNA, & Proteins RNA Structure (Single Stranded):

Uracil, NOT

Thymine

Image Source: http://commons.wikimedia.org/wiki/File:Difference_DNA_RNA-EN.svg

DNA, RNA, & Proteins RNA can fold into itself:

Image Source: www.uic.edu

DNA, RNA, & Proteins 3 Types of RNA:

mRNA rRNA tRNA“messenger” “ribosomal” “transfer”

Carries genetic info from DNA (in nucleus) to

ribosome (in cytoplasm)Combines with a protein

to form the ribosomeTransports amino acids

to the ribosome

rRNA Image Source: www.sparknotes.comtRNA Image Source: www.wiley.commRNA Image Source: www.yalescientific.org

DNA, RNA, and Proteins Proteins are essential to life: antibodies, enzymes,

hormones, structure, storage, transport, etc. A macromolecule made of linked monomers called

amino acids:

H2N C COOH

H

R

-NH2 (amine group)-COOH (carboxylic acid)

Side chain different from each of the 20 amino acidsImage Source: commons.wikimedia.org

DNA, RNA, and Proteins Proteins: Complex 3D

Structure Primary Structure: order of

amino acids in a protein (a.k.a. “polypeptide chain”).

Secondary Structure: coiling or pleating.

Tertiary Structure: coils & pleats attract each other.

Quaternary Structure: multiple proteins grouped together.

Image Source: www.contexo.info

DNA, RNA, and Proteins Only 20 amino acids, BUT:

Any NUMBER of amino acids Any ORDER of amino acidsMillions of Protein Combinations!

Image Source: www.irbbarcelona.org

Semiconservative Replication

Problems A T T C G A T G C C A A A T G G C G A

C C T G C G A T C C A T T C G A G A T

T T A C A T A A G C G C C C T A T C G

A A A T A C G A T T G G C G A A T A T

Reading/Work Time Packet Work: Cornell Notes for the following:

Section 11.1 Section 11.2 Section 11.3

Questions: 11.1: #1-3 11.2: #1-3 11.3: #1-3 Chapter 11 Assessment: #1-2, 8-11, 13, 16, 18