Chapter 3 Biochemistry. I. Carbon Compounds Inorganic vs. Organic Inorganic compounds do not contain...
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Transcript of Chapter 3 Biochemistry. I. Carbon Compounds Inorganic vs. Organic Inorganic compounds do not contain...
Chapter 3
Biochemistry
I. Carbon Compounds
• Inorganic vs. Organic• Inorganic compounds
do not contain carbon atoms
• Organic compounds contain carbon atoms
Carbon Bonding
• Carbon has 4 electrons in its outer shell– It wants to gain 4 more to become
stable with 8– Carbon readily forms four covalent
bonds with atoms of other elements– Carbon is unique from other
elements because it can bond with other carbon atoms
– Because of all the preceding, carbon is able to form an enormous variety of organic bonds
• Single Bond-sharing one pair of electrons
• Double Bond-sharing two pair of electrons
• Triple Bond-sharing three pair of electrons
Functional Groups
• Clusters of atoms that influence the properties or characteristics of the molecule
Large Carbon Molecules
• Monomers- a simple molecule, smallest subunit
• Polymers- made of repeating monomers
• Macromolecules- made up of large polymers
• Condensation Reactions- release a molecule of water to form a bond
• Hydrolysis- water
• is added to break
• a polymer
You Down with ATP?
• Cells run on energy in the form of ATP– Adenosine triphosphate– Phosphate groups
attached by covalent bonds, which store high amounts of energy
II. Molecules of Life
• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids
Carbohydrates
• Composed of carbon, hydrogen, and oxygen in a ratio of 1C:2H:1O, Serve as a source of energy or used for structural materials
• Monosaccharides- a monomer of a carbohydrate (glucose, fructose and galactose)
• Disaccharides- two monosaccharides or a double sugar (glucose + fructose = sucrose)
• Polysaccharides- three or more monosaccharides
• Animals store glucose in the form of the polysaccharide glycogen
• Plants store glucose as the polysaccharide starch
• Strength and rigidity in plants is caused by the structure of the polysaccharide cellulose
Proteins
• Composed mainly of carbon, hydrogen, oxygen, and nitrogen, provide structure for cells
• Amino acids-monomers of protein (building blocks)
• Dipeptides-two amino acids held together by a peptide bond
• Polypeptides- three or more amino acids, held together by peptide bonds
Amino Acids
• 20 different amino acids• All contain
– Central carbon
– Amino group
– A carboxyl group (COOH)
– A single hydrogen
– R group (the only thing different between the 20 amino acids) influences the properties of the amino acid
Peptide Bond
• Covalent bond linking two amino acids
• A condensation reaction (water is formed and released)
• Long chains of amino acids has positive and negative regions which fold to give protein molecules unique shapes
• The shapes can be denatured when heated
Enzymes• RNA or protein
molecules that act as biological catalysts
• Depend on the fit between– Substrate
– Enzymes active site
Lipids
• Long chains of carbon with many hydrogens
• Function is to store energy
• Include: fatty acids, triglycerides, phospholipids, waxes, steroids
Fatty Acids
• Unbranched carbon chains that make up most lipids
• Long chain of carbon with a carboxyl group at one end
• Carboxyl end is polar and therefore hydrophilic• Hydrocarbon end is nonpolar and therefore
hydrophobic• Fatty acids include triglycerides, phospholipids,
and waxes
• Saturated Fatty Acids– Carbon atoms fully saturated with hydrogens
• Unsaturated Fatty Acids– Carbon atoms with double bonds
Triglycerides
• 3 molecules of a fatty acid joined to one molecule of the alcohol glycerol
• Saturated triglycerides have high melting points and are hard at room temp (butter and fats in red meat)
• Unsaturated are usually soft or liquid at room temp and found in plant seeds (olive oil)
Phospholipids
• Two fatty acids attached to a molecule of glycerol and a phosphate group attached to the third carbon of the glycerol
• Help make up the cell membrane
• Lipid bilayer– Hydrophobic head– Hydrophilic tail
Waxes
• A long fatty acid chain connected to a long alcohol chain
• Waterproof• Help form protective
coating in plants and animals (earwax)
Steroids
• Four fused carbon rings with various functional groups
• Hormones• Cholesterol
Nucleic Acids• DNA
– Contains information that determines the characteristics of an organism and directs cell activities
• RNA– Stores and transfer information of DNA to make
proteins
• Composed of nucleotides– Sugar– Phosphate– Base
Review
• What do all organic compounds contain?– Carbon
How many electrons are shared in a double bond?
• 4 electrons (aka 2 pair)
How many electrons does carbon want to gain?
• 4 electrons
What is the smallest subunit
• Monomer
• What is the monomer of carbohydrates?– monosaccharides
• What is the monomer of proteins? – Amino acid
• How do animals store glucose?– Glycogen
• How do plants store glucose?– Starch
• What are the polymers of carbohydrates– polysaccharides
• What are the polymers of protein?– Polypeptides
• What are the only two macromolecules that contain nitrogen?– Proteins
– Nucleic Acids
• Which macromolecule is nonpolar?– Lipids