Ch.2 Flashcards
(15 cards)
Organic molecules
Proteins
Nucleic acids
Carbohydrates
Lipids
Proteins
Provide structural support and act as catalysts to facilitate chemical reactions
Made of amino acid subunits
Also called polypeptides because of peptide bonds
Nucleotides-the building blocks of nucleic acids
Composed of
5 carbon sugar (ribose or deoxyribose)
Base containing nitrogen
One or more phosphate groups
Nucleotide bases
- Pyrimidine bases-single ring
Cytosine (C)
Thymine (T)
Uracil (U) - Purine bases-double ring
Guanine (G)
Adenine (A)
Bonds between nucleotides
Adjacent pairs are joined by phosphodiester bonds
The phosphate group of one nucleotide is joined to the sugar unit in another
The formation results in the loss of a water molecule
Structure of DNA
Sugar phosphate backbones wrap around the outside and the bases form complementary base-pairing A-T G-C by hydrogen bonds
Hydrogen bonds allow unzipping of DNA during replication and transcription
Carbohydrates (sugar)
Composed of C, H, and O
Types of sugar molecules
Monosaccharide
Disaccharide
Polysaccharide
Monosaccharide
Contains one sugar molecule
Often a subunit, or monomer, of more complex sugars
Virtually all in a cell are in cyclic form
Disaccharide
Contain two bonded monosaccharides
Polysaccharide
Contain more than two monosaccharide monomers, and are formed through dehydration reactions
Complex carbohydrates
Long, braided chains of monosaccharide monomers
Lipids: fatty acids
Hydrophobic
Long chains of carbons attached to a carboxyl group
Lipids: steroids
Composed of many carbon atoms bonded to form rings
Lipids: phospholipids
Major component of cell membrane
Polar head group (hydrophilic)
Non-polar tails (hydrophobic)
