biological molecules 3.1 Flashcards
aqa biology as level
what is a monomer?
small units that can create larger molecules
what is a polymer?
a molecule made from repeated units called monomers
what are examples of monomers?
glucose amino acids and nucleotides
what polymers can glucose make?
starch glycogen and cellulose
what polymer do amino acids make?
proteins
what polymer do nucleotides make?
DNA and RNA
what is a condensation reaction?
two molecules joining by forming a chemical bond and the removal of one water molecule
what is a hydrolysis reaction?
the breaking of a chemical bond between two molecules involving the use of water
what bond is formed between the condensation reaction of two monosaccharides?
glycosidic bond
how is a disaccharide formed?
condensation reaction between two monosaccharides
what molecules form maltose?
two glucose molecules through condensation reactions
what molecules form sucrose?
glucose and fructose molecules through condensation reactions
what molecules form lactose?
glucose and galactose molecules through condensation reactions
what are the isomers of glucose?
alpha glucose and beta glucose (OH and H group inverted)
what is the polymers of alpha glucose?
starch and glycogen
how are polysaccharides formed?
formed through the condensation of many glucose monomers
what is the polymer of beta glucose?
cellulose
what is the structure and function of starch?
- found in plants (plant cells) and used to store glucose
- a glucose
- 1,4 and 1,6 glycosidic bonds
- highly branched
- helical and compact
- insoluble
what is the structure and function of glycogen?
- found in animals (muscle cells) and used to store glucose
- a glucose
- 1,4 and 1,6 glycosidic bonds
- highly branched
- insoluble
what is the structure and function of cellulose?
- found in plants (cell wall) and used to strengthen plant
- b glucose
- 1,4 glycosidic bonds
- form long straight chains which are held together by h bonds to form fibrils
- many h bonds provide collective strength
- insoluble
what are two groups of lipids?
triglycerides and phospholipids
how are triglycerides formed?
a condensation reaction between 3 fatty acids and a glycerol molecule
how are phospholipids formed?
a condensation reaction between 2 fatty acids a phosphate and glycerol moleule
what bond forms between a glycerol and fatty acid (RCOOH)?
ester bond
what are the types of R groups in fatty acids?
unsaturated and saturated
what is a saturated fatty acid?
only contain carbon single bonds between carbon atoms in hydrocarbon chains
what is a unsaturated fatty acid?
contains one or more carbon double bond between carbon atoms in hydrocarbon chain
what are the properties of a triglyceride?
- high energy storer
- metabolic water source
- insoluble
- low mass so can be stored compactly
what are the properties of a phospholipid?
- hydrophilic head due to negative charge on phosphate
- hydrophobic tail
- two charged regions so polar
how is the plasma membrane structured?
phospholipid bilayer hydrophobic tails point inwards and hydrophilic heads point outwards to water
what is the amino acid structure?
: R
I
H2N —- C —- COOH
I
H
how is a dipeptide formed?
condensation reaction between two amino acids