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 & Develop Respond to changes in their environment Reproduce Process energy Adapt How 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.

Biochemistry The study of biologically important reactions and the molecules and processes involved in them is called biochemistry.

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

Cell Membrane Phospholipids = hydrocarbon chains with phosphate group 3nm to 10 nm thick The 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

Metabolism metabolic 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

Metabolism Each 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!

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

Elements The 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

ElementExample role in plantsExample role in animals IronIn cytochromesIn cytochromes and in hemoglobin SulfurIn some amino acids CalciumCo-factor in some enzymesCo-factor in some enzymes and component of bones PhosphorousPhosphate groups in ATP and phospholipids SodiumIn membrane functionIn membrane function (Na- K pump) and sending nerve impulses PotassiumProvides the necessary environment for metabolic activities Major cation inside the cell. Used in neurotransmission, muscle contraction, etc