Topic #2: Molecular Biology

Molecules to Metabolism 2.1

What must cells do to stay alive?

Maintain regulation - Get rid of wastes, ingest food and water

Grow & DevelopRespond to changes in their environmentReproduceProcess energyAdaptHow does each cell do this?

Living organisms are collections of elements in the form of atoms, ions, and molecules.

Living things rely on chemical reactions, which take place at the molecular level.

You rely on your cells to perform trillion of chemical reactions every second.

BiochemistryThe study of biologically

important reactions and the molecules and processes involved in them is called biochemistry.

http://www.youtube.com/watch?v=tpBAmzQ_pUE

Molecular Biology

Molecular biology explains living processes in terms of the chemical substances involved

Examples?

Cell MembranePhospholipids = hydrocarbon chains with

phosphate group3nm to 10 nm thickThe cell maintains a sophisticated barrier

between itself and the outside world Prior to knowing what the cell membrane

actually looked like, scientists used chemical knowledge and procedures to make inferences

Metabolism

Web of enzyme-catalysed reactions in a cell or organism

Metabolismmetabolic reactions and processes that

take place in the cells of organisms can convert energy from nutrients into ATP

CATABOLISM = the breakdown of complex molecules into simpler molecules

MetabolismEach cell uses energy to build the

structures it needs from materials available in its external environment – atoms and molecules.

ANABOLISM = the synthesis of complex molecules from simpler molecules

The periodic table for biologists

The Element song! http://www.youtube.com/watch?v=v1TfPDlA1xE

Chemistry Review

Periodic Table Metals and non-metals Element, Ion, Compound Valence electrons Covalent bonds

ElementsThe 4 most common elements found in living

things are carbon, hydrogen, oxygen and nitrogen.

Used in the molecular structures of all carbohydrates, proteins, lipids, and nucleic acids.

Organic Chemistry

the scientific study of the structure, properties, and reactions of matter in its various forms that contain carbon atoms

Hydrocarbons

worksheet

Carbon and Hydrogen

Carbon and hydrogen are the backbone of organic molecules, sugars and carbohydrates, amino acids and

proteins, and lipids (fats and oils) Hydrogen ions (H+) are used in active

transport, photosynthesis and cell respiration

Carbon and Hydrogen

Life is based on carbon compounds Carbon atoms form 4 covalent bonds

Allowing diversity of stable compounds

Oxygen

Main role is to allow aerobic respiration to occur. This is the last stage of cell respiration (much more of this to come!)

Oxygen is also used in oxidation reactions where oxygen is put into ATP to release energy into tissues.

Nitrogen

The main use of nitrogen is in the production of amino acids. Amino acids are transformed into proteins.

Nitrogen is also used in chlorophyll.

Functions of other elements

a variety of other elements are needed by living organisms, including sulfur, calcium, phosphorous, iron, and sodium.

Get out your cell phones…Find one role for each of the elements

above…. Go

Element Example role in plants Example role in animals

Iron In cytochromes In cytochromes and in hemoglobin

Sulfur In some amino acids In some amino acids

Calcium Co-factor in some enzymes Co-factor in some enzymes and component of bones

Phosphorous Phosphate groups in ATP and phospholipids

Phosphate groups in ATP and phospholipids

Sodium In membrane function In membrane function (Na-K pump) and sending nerve impulses

Potassium Provides the necessary environment for metabolic activities

Major cation inside the cell. Used in neurotransmission, muscle contraction, etc