molecular cell biology 1 basics of molecular biology

The Main Functions of the Membrane-bounded Compartments of a Eukaryotic Cell Cytosol contains many metabolic pathways protein synthesis Nucleus contains main genome DNA and RNA synthesi

Course in Molecular Biology

Leuven, October – November 2002

Program

I Basics of molecular biology

II Transcription III Translation

IV Regulatory pathways

V DNA and diseases

VI Biotechnology

Lesson 1: Basics of molecular biology

I The Cell’s Organization

II Cell Cycle and Cell Division

III Cellular Molecules

IV The Genetic Dogma

The Cell’s Organization

All organisms: 1 or more cells

The animal cell

A plant cell

A bacterium

The Main Functions of the Membrane-bounded

Compartments of a Eukaryotic Cell

Cytosol contains many metabolic pathways

protein synthesis Nucleus contains main genome

DNA and RNA synthesis Endoplasmic reticulum

(ER) synthesis of most lipidssynthesis of proteins for distribution to many organelles and plasma

membrane Golgi apparatus modification, sorting, and packaging of proteins and lipids

for either secretion or delivery to another organelle Lysosomes intracellular degradation

Compartimentation of the eukaryote cell:

various organelles

Cell nucleus

Contains genetic information: DNA

Each human cell contains 46 chromosomes (except sperm or egg cells)

in a cell that is about to divide

H 2 O

CO 2

The endoplasmic reticulum

smooth (metabolism+synthesis of lipids) rough (protein synthesis)

The Golgi apparatus

medial

Inside the cytosol:

the cytoskeleton

 “microtubules”

 maintainance of cell shape and mobility

 ancor for other cellular structures

DNA

Cell Cycle and Cell Division

Some Eukaryotic Cell-Cycle Times

The eukaryotic cell cycle

Separation of sister chromatides during mitosis

(mitosis = normal cell division)

assist chromosomes during cell division (mitosis)

Different stages of the M phase during cell division (mitosis)

The three DNA sequence elements needed to produce a eukaryotic chromosome that can be replicated and then segregated at mitosis

Kinetochores and kinetochore microtubules

Meiosis I (continued) Meiosis II

Presentation:

Chromosomes, mitosis and meiosis

Cellular Molecules

The four main families of small organic molecules in cells

Macromolecules are abundant in cells

The general reaction by which a macromolecule is made

Condensation reaction: H 2 O molecule is released

The four main families of small organic molecules in cells

Glucose, a simple sugar

Monosaccharides

Sugar ring formation in aqueous solution

formed by two sugar monomers

Oligo- and polysaccharides

Complex oligosaccharides

The four main families of small organic molecules in cells

Phospholipid structure and orientation of phospholipids in membranes

The four main families of small organic molecules in cells

A simple amino acid: alanine

A small part of a large protein molecule

The four main families of small organic molecules in cells

the energy carrier in cells

Various functions of proteins

Proteins as polypeptide chains

Three types of noncovalent bonds that help proteins fold

The size of proteins

Several levels of protein organization

Many protein molecules contain multiple copies

of a single protein subunit

Proteins often have highly specific binding sites

How a set of enzyme-catalyzed reactions generates a metabolic pathway

Phosphorylation and ATP hydrolysis drive protein functions

Genetic information is stored in the DNA

DNA and its building blocks

DNA has an orientation

DNA encodes proteins

“Genes” encode proteins

DNA replication

DNA synthesis and proofreading

Replication of eukaryotic chromosomes

The replication fork in detail

DNA replication can cause mutations

DNA repair

possible cause of diseases and disfunctionalities

The Genetic Dogma

From DNA to protein

Transcription by RNA polymerase

RNA vs DNA

Genes contain introns and exons

Heredity and inheritance