Nucleus

DNA

DNA Packaging Inside Nucleus

Nucleosome

Supercoil

ProteinScaffoldChromosome

Double Helix (Partially Disrupted)

2 nanometers

1 turn =

10 base pairs = 3.4 nanometers

Major Groove

Minor Groove

NUCLEOTIDES

Phosphate

Sugar

Base

TRIPLET CODONS

UGA

GENETIC CODE  Initiation Codon   Termination Codons

  U C A G

U

UUU Phe UCU Ser UAU Tyr UGU Cys

UUC Phe UCC Ser UAC Tyr UGC Cys

UUA Leu UCA UAASer  

UUG Leu UCG Ser UAG   UGG Trp

C

CUU Leu CCU Pro CAU His CGU Arg

CUC Leu CCC Pro CAC His CGC Arg

CUA Leu CCA Pro CAA Gln CGA Arg

CUG Leu CCG Pro CAG Gln CGG Arg

A

AUU Ile ACU Thr AAU Asn AGU Ser

AUC Ile ACC Thr AAC Asn AGC Ser

AUA Ile ACA Thr AAA Lys AGA Arg

AUG Met ACG Thr AAG Lys AGG Arg

G

GUU Val GCU Ala GAU Asp GGU Gly

GUC Val GCC Ala GAC Asp GGC Gly

GUA Val GCA Ala GAA Glu GGA Gly

GUG Val GCG Ala GAG Glu GGG Gly

UGAUAA

UGA

AUG

First Base

in Codon

Third Base

in Codon

•Controlling what goes in and out of the cell.

•Anchoring of the cytoskeleton to provide shape to the cell

•Attaching to the extracellular matrix to help group cells together in the formation of tissues

•Transportation of particles by way of ion pumps, ion channels, and carrier proteins• •Containing receptors that allow chemical messages to pass between cells and systems

•Participation in enzyme activity important in such things as metabolism and immunity

CELL MEMBRANE

CELL MEMBRANEThe cell mem consists of three classes of amphipathic lipids: PHOSPOLIPIDS, GLYCOLIPIDS, STEROIDS

Membrane is held together via weak non-covalent interaction of hydrophobic tails Structure is fluid and not fixed rigidly in place.

Phospholipid molecules are “fluid”: free to diffuse and exhibit rapid lateral diffusion along the layer they are present in.

The FATTY ACID chains in phospholipids and glycolipids usually contain an even number of carbon atoms, typically between 14 and 24. The 16- and 18-carbon fatty acids are the most common.

In animal cells, cholesterol is found dispersed in varying degrees throughout cell membranes, where it confers a stiffening and strengthening effect on the membrane. It resides in the irregular spaces between the hydrophobic tails of the membrane lipids.

polar, hydrophilic heads

hydrophobic tails

||7nm||

SELECTIVE TRANSPORT OF MOLECULES ACROSS MEMBRANE

Nutrients: in Waste: out

Gate Keepers: Transmembrane PROTEINS

Create: ion channels, proton pumps, etc.

Extremely important to cell: e.g. a third of the genes in yeast code specifically for them

Again: chicken and eggNeed DNA to code for membrane proteins butNeed membrane proteins to create selective membrane to allow cell to exist.