Biomolecules Carbohydrates Proteins, Lipids, and Nucleic acids.
-
Upload
albert-young -
Category
Documents
-
view
283 -
download
1
Transcript of Biomolecules Carbohydrates Proteins, Lipids, and Nucleic acids.
Carbon is the central element
• All biomolecules contain a Carbon chain or ring
• Carbon has 4 outer shell electrons (valence = 4)
• Therefore it’s bonding capacity is great
• It forms covalent bonds –hence, has strong bonds
• Once bound to other elements (or to other
Carbons), it is very stable
Carbon binds to more than just hydrogen
• To OH groups in sugars
• To NH2 groups in amino acids
• To H2PO4 groups in nucleotides of DNA, ATP
Amino acid
These are called ‘functional groups’!
Carbohydrates (or sugars)
• Simple sugars (monosaccharides)
• Only one 6-C chain or ring involved
• General formula
(CH2O)
Carbohydrates (sugars)
• Double sugars (disaccharides)
• Two 6-C chains or rings bonded together
Lactose
Carbohydrates (sugars)
• Complex carbo’s (polysaccharides)– Starch –energy storage
– Cellulose – structural support
– Glycogen – energy storage
– Chitin – structural
Glycogen to glucose in animals
Up to 10,000 glucose units!!
Proteins• Composed of chains
of amino acids
• 20 amino acids exist
• Amino acids contain– Central Carbon
– Amine group
– Carboxyl group
– R group
There are four levels of protein structure
• Primary = sequence of aa’s
• Secondary = forms pleated sheet, helix, or coil
• Tertiary = entire length of aa’s folded into a shape
• Quaternary = several aa sequences linked together
1º 2º
3° 4°
Shape is critical to protein function
Types of proteins
• Enzymes• Hormones• Structural proteins• Receptor proteins
Nucleic acids: DNA and RNA
• DNA = deoxyribonucleic acid
• DNA is a double polymer (chain)
• Each chain is made of nucleotides
• The 2 chains bond together to form a helix
DNA nucleotides – double stranded polymer
• Each nucleotide in DNA contains:– 5-C sugar
(deoxyribose)
– Phosphate
– Nitrogen base
-adenine (A)
-guanine (G)
-cytosine (C)
-thymine (T)
RNA Nucleotides – single-stranded polymer
• Each nucleotide in RNA contains:– 5-Carbon sugar –
Ribose***
– Phosphate
– Nitrogen base• Adenine (A)
• Guanine (G)
• Cytosine ©
• Uracil (U)***
Lipids• Made of the same
elements as carbohydrates, but insoluble in water
• Do not form polymers!• Major function:
– Energy storage
– Insulation
– Cell membranes
Types of lipids1- glycerides
• Make up 90% of lipid in food
• Differ with respect to ‘saturated’ or ‘unsaturated’ fatty acid chains
Types of lipids2- steroids
• Contain a central core of 4 rings
• Difference in functional groups relates to steroid function in the body
• 3 main forms of steroids– Cholesterol– Estrogen– testosterone
Lipids and Health
• Hierarchy of dietary fats:– Fats containing
Omega-3 fatty acids
– Mono- and poly unsaturated fats
– Saturated fats
– Trans fats