Week 3 Flashcards
All living cells are composed of 4 major groups of compounds. What are they?
- Carbhoydrates - form giant sugar molecules
- Fats - form larger structures
- Proteins - made from combinations of amino acids (20)
- Nucleic acid - formed from 4 kinds of nucleotide monomers (identical molecules)
What is a monosaccharide?
Monosaccharides: chain of 3 or more carbon atom, 1 of which forms a carbonyl group through a double bond with oxygen. E.g. glucose, ribose and fructose.
What are disaccharides?
Disaccharides consists of two monosaccharides linked together by glycosidic bonds (colvalent bonds). E.g. sucrose (table sugar) is made up of glucose and fructose through a condensation reaction.
What are oligosaccharides? Do they usually have functional groups or bound to other things?
- Made up of several (3-20) monosaccharides bound by glycosidic linkages (through condensation)
- Many have additional functional groups, which give them special properties
- Oligosaccharides are often covalently bonded to proteins and lipids on the outer cell surface, where they serve as recognition signals (e.g. different human blood groups (e.g ABO blood types) are oligiosaccharides
What are polysaccharides?
Polymers made up of hundreds or thousands of monosaccharides (e.g. starch, glycogen and cellulose)
What are some of the different types of lipids? And what are some of the different functions?
- fats and oils store energy
- phospholipids have structureal roles in cell membranes
- Steroids and modified fatty acidsd play regulatory roles as hormones and vitamins
Differenct functions:
- thermal insulation
- lipid coating around nerves provides electrical insulation
- oil or wax on surfaces of skin, fur and feathers repel water
Are monosaccharides, disaccharides, oligosaccharides and polysaccharides carbohydrates or a lipids?
They are carbhoydrates!
Are fats and oils triglycerides or glycerol?
- Fat and oils are triglycerids.
- Triglycerides are composed of two components: fatty acids (long nonpolar hydrocarbon chain and a polar carbxyl group) and glycerol (molecules with 3 hydroxyl groups)
- Triglyceride has 3 fatty acid molecules and one glycerol
- Made through 3 condensation reactions
- Carboxyl group of fatty acid bonds with hydroxyl group of glycerol, that make ester linkage (covalent bond) and release of a water molecule
What does it mean to be a saturated fatty acid?
Saturated fatty acids have no double bonds between carbons - it is saturated with H atoms. Thes fatty acid molecules are relativey rigid and straight, and they pack together tightly.
What does it mean to be an unsaturated fatty acid? What does monounsaturated and polyunsaturated mean?
- Unsaturated fatty acids: some double bonds in carbon chain
- Monounsaturated: one double bond
- Polyunsaturated: more than one
Unsaturated fatty acids pack together poorly and have a low melting point, and these triglycerides are usually liquids at room temperature.
Does fats or carbohydrates give more energy?
On a per weight basis, broken-down fats yield more than twice as much energy as degraded carbohydrates.
What gives phospholipids amphipathic properties?
- The phosphate group has a negative electric charge and is hyrophilic. The two fatty acids are hydrophobic, so avoid water and aggregate together or with other hydrophobic substances.
- They form a bilayer: water excluded from the core
What are some of the different forms and functions of proteins?
- Enzymes are catalytic proteins that speed up biochemical reactions
- Defensive proteins such as antibodies
- Hormonal & regulatory proteins (insulin’s control of physiological processes
- Receptor proteins, respond to molecular signals (insulin receptor)
- Storage proteins - chemical building blocks (amino acids)
- Structural proteins such as collagen provide physical stablity and movement
- Transport proteins such as hemoglobin carry substances within an organism
- Genetic regulatory proteins regulate when, how and what gene is expressed
- Energy storage and information storage ARE NOT USUALLY PERFORMED BY PROTEINS
Amino acids are the building blocks of proteins. What functional groups do amino acids have?
Amino acids have a carboxyl functional group and an amino functional group. Also attached are a hydrogen atom and a R functional group.
Amno acids exist in two isomeric forms. D- amino acids and L-amino acids. Where side is the amino group placed in each isomeric form and which form is more common?
D-amino acids: amino group right; dextro.
L-amino acids: amino group lfe; levo; most common
