Topic 1 - Biological molecules Flashcards
what type of molecules are carbohydrates ?
Carbohydrates
polymers
what are polymers ?
Monomers and Polymers
large complex molecules composed of long chains of monomers joined together
what are monomers ?
Monomers and Polymers
small, basics molecular units that join together to form polymers
name 3 monomers
Monomers and Polymers
monosaccharides, amino acids and nucleotides
what elements to all carbohydrates contain ?
Carbohydrates
C, H and O
what monomers are carbohydrates made from ?
Carbohdrates
monosaccharides
name 3 monosaccharides
Carbohdrates
glucose, galactose and fructose
what are monosaccharides
Carbohdrates
sugar molecules that create polymers
what type of molecule is glucose and what does this mean
Carbohdrates
hexose sugar - a monosaccharide with 6 carbon atoms in each molecule
what are the two types of glucose ?
Carbohdrates
alpha glucose and beta glucose
Draw the structure of alpha glucose
Carbohdrates
.
Draw the structure of beta glucose
Carbohdrates
.
what’s an isomer
Carbohdrates
molecules with the same formula as each other but the atoms are connected differently
what’s a condensation reaction ?
Monomers and Polymers
two molecules join together with the formation of a new chemical bond and the release of a water molecule
what is a disaccharide ?
Carbohdrates
two monosaccharides joined together
what bond is formed during a condensation reaction for carbohydrates
Carbohdrates
1,4 glycosidic bond
glucose + glucose =
Carbohdrates
maltose
glucose + galactose =
Carbohdrates
lactose
glucose + fructose =
Carbohdrates
sucrose
what happens during a hydrolysis reaction
Monomers and Polymers
polymers are broken down into monomers by breaking the chemical bond using a water molecule
what disaccharides are reducing sugars ?
Carbohdrates
maltose and lactose
list the method for testing for reducing sugars
Carbohdrates
- Add blue benedict’s reagent to the sample and heat it in a water bath that’s been brought to the boil.
- if the test is positive a coloured precipitate will form
what is the colour scale for positive reducing sugar test ?
Carbohdrates
blue, green, yellow, orange, brick red
Give an accurate way to compare the amount of reducing sugars in a solution
Carbohdrates
filter the solution and weigh the precipitate
what disaccharide is a non reducing sugar
Carbohdrates
sucrose
list the method for testing for non reducing sugars
Carbohdrates
- Add dilute hydrochloric acid to the food sample and heat it in a water bath that’s been brought to the boil.
- Add sodium hydrogencarbonate to neutralise it.
- Add blue benedict’s reagent and heat in a water bath that’s been brought to the boil.
4.if the test is positive a coloured precipitate will form depending on the concentration of the non reducing sugar.
What is a polysaccharide and how is it formed
Carbohdrates
A polymer formed when more than 2 monosaccharides are joined together by condensation reactions
What are the three polysaccharides
Carbohdrates
starch, glycogen and cellulose
in plants, what’s alpha glucose stored as
Carbohdrates
starch
What’s starch a mixture of
Carbohdrates
two polysaccharides of alpha glucose: Amylose and amylopectin
Describe the structure and function of amylose
Carbohdrates
long, unbranched chains of alpha glucose. The angles of the 1,4 glycosidic bonds give it a coiled shape making it compact and good for storage as you can fit more into a smaller space.
describe the structure and function of amylopectin
Carbohdrates
long, branched chains of alpha glucose. it’s side branches allowed the enzymes that break down the molecule to get to the glycosidic bonds easier so glucose can be released quickly. made from 1,4 and 1,6 glycosidic bonds.
Give a positive of starch
Carbohdrates
it’s insoluble in water so doesn’t affect water potential meaning it won’t draw water into cells by osmosis which prevents them from swelling, making it good for storage.
give the method for testing for starch
Carbohdrates
- Add iodine dissolved in potassium iodide solution to the food sample
- if the test is positive the colour will change from orangey brown to blue back
what’s glycogen’s role
Carbohdrates
to store glucose in animals so it is the main energy source for animals
what type of molecule is glycogen
Carbohdrates
polysaccharide of alpha glucose
describe the structure and function of glycogen
Carbohdrates
it is made from long branched chains meaning that enzymes can reach the binds easily so stored glucose can be released quickly which is important for energy release in animals. It’s also a very compact molecule so is good for storage as more can fit into a smaller space. 1,4 and 1,6 glycosidic bonds.
what type of molecule is cellulose
Carbohdrates
polysaccharide of beta glucose