ch. 2 part 2
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Ch. 2 Part 2. The Chemical Level of Organization. Inorganic vs. Organic. Inorganic Usually lack carbon Structurally simple Include: Water Salts Acids Bases Exceptions Carbon dioxide (CO 2 ) Bicarbonate (HCO 3 - ) Carbonic acid (H 2 CO 3 ). Organic Always contain carbon - PowerPoint PPT PresentationTRANSCRIPT
Ch. 2Part 2
The Chemical Level of Organization
Inorganic vs. Organic
• Inorganic– Usually lack carbon– Structurally simple– Include:
• Water• Salts• Acids• Bases
– Exceptions• Carbon dioxide (CO2)
• Bicarbonate (HCO3-)
• Carbonic acid (H2CO3)
• Organic– Always contain carbon– Usually contain
hydrogen– Always have covalent
bonds– Most are large
molecules made up of long chains
Role of Water in the Body
• Most important inorganic compound for life• Almost all chemical reactions in the body need
water to occur• Water is a solvent – dissolves important
substances• Water has high heat capacity – doesn’t change
temperatures easily• Water also acts as a lubricant (mucus) for joints,
food movement, and between thoracic organs
Acids and Bases
• This is also a review• pH scale – 0-14• Acids (0-6)– Dissociate into hydrogen (H+) ions– Example: HCl
• Bases (0-14)– Dissociate into hydroxide (OH-) ions– Example: NaOH
Acids and Bases in the Body
• Buffer system – the body’s ability to control pH of certain fluids
• Example:– Blood should have a pH of 7.35-7.45– If the pH of blood gets to high or too low, serious
complications can occur– A buffer system can help correct a pH imbalance• Does this by converting strong acids or bases into weak
acids or bases
Organic Compounds of the Body
• Organic compounds contain carbon
• Organized into various structures– Macromolecules – large
molecules– Polymers – built by putting
together repeating monomers
Organic Compounds in the Body
• In order to make a macromolecule– Dehydration synthesis must occur– Removing a water molecule, bind to monomers
together– XOH + YOH → XOY + H2O
• In order to break a macromolecule– Hydrolysis must occur– Adding a water molecule, break to monomers apart– XOY + H2O → XOH + YOH
4 Major Groups of Organic Compounds
• Carbohydrates• Lipids• Proteins• Nucleic Acids
Carbohydrates
• Include: sugars, glycogen, starches, cellulose• Examples in our diet– Bread, pasta, rice, cereal
• Function as a source of chemical energy (quick energy)
• Made of carbon, hydrogen, and oxygen• 3 major groups– Monosaccharides– Disaccharides– polysaccharides
Carbohydrates
• Monosaccharides – one sugar (sweet)– Glucose, fructose, galactose
• Disaccharides – two sugars (sweet)– Sucrose, lactose, maltose
• Polysaccharides – many sugars (not sweet)– Glycogen, starch, cellulose
Lipids
• Include: triglycerides, phospholipids, steroids• Examples in our diet:– Fats, oils
• Function as a source of energy storage• Made of carbon, hydrogen, and oxygen• Are hydrophobic – do not dissolve in water• Lipids are made of repeating fatty acids
Lipids
• Triglycerides– Saturated fats – only single covalent bonds– Monounsaturated fats – one double bond– Polyunsaturated fats – more than one double bond
• Phospholipids– Important part of cell membrane
• Steroids– Important part of cell membrane, not all steroids
are anabolic
Proteins
• Include: proteins and enzymes• Examples in our diet:– Meat, fish, eggs, milk
• Function as catalysts, protect against invaders, hormones, cell transport, building blocks of body
• Made of carbon, hydrogen, oxygen, nitrogen, sulfur
• Proteins are made of repeating amino acids
Proteins• 20 different amino acids• Amino acids are joined by peptide bonds to
create polypeptide chains• Enzymes– Speed up chemical reactions within the body
Nucleic Acids
• Include: DNA and RNA• Examples in our diet:– none – but we eat the building blocks (amino
acids)• Function as inherited genetic material• Made of carbon, hydrogen, oxygen, nitrogen,
and phosphorous• Made of repeating chains of nucleotides
Nucleic Acids
• Nucleotides have 3 parts– Sugar– Phosphate– Nitrogenous base
ATP
• Adenosine triphosphate• ATP is not one of the 4 major groups of
organic molecules• ATP is essential to life – energy source