biological molecules Flashcards
can you explain that all living things have a similar biochemical basis
All living things contain carbohydrates, lipids, protein and nucleic acids. Carbohydrates and lipids are mostly used by cells as respiratory substrates. Lipids are consisted in the bilayer of plasma membrane and in hormones. Proteins form many cell structures and nucleic acids carry the genetic code for the production of proteins.
can you describe what a monomer and polymer is and name examples of monomers.
monomers are the smaller units from which larger molecules are made, examples of monomers are monosaccharides, amino acids and nucleotides. Polymers are molecules that are made from a large number of monomers joined together
what is a condensation reaction.
A condensation reaction joins two molecules together with the formation of a chemical bond and involves the elimination of a molecule of water
what is a hydrolysis reaction
A hydrolysis reaction breaks a chemical bond between two molecule and involves the use of a water molecule
describe how carbohydrates are made from monosaccharides, names examples of monosaccharides.
monosaccharides are the monomers from which larger carbohydrates are made. Examples of monosaccharides are fructose, galactose and glucose
a condensation reaction between two monosaccharides form what bond
glycosidic bond
how are disaccharides formed
Disaccharides are formed by the condensation of two monosaccharides
name all the disaccharides
sucrose, maltose and lactose
how is sucrose, lactose and maltose formed
sucrose is formed by the condensation of a glucose molecule and a fructose molecule.
lactose is formed by the condensation of a glucose molecule and a galactose molecule.
maltose is formed by the condensation of two glucose molecules.
name two glucose isomers and draw the structure both
Alpha glucose and beta glucose.
describe what a polysaccharide is
a polysaccharide are formed by the condensation of many glucose units
what type of glucose are cellulose, starch and glycogen made of
starch and glycogen is formed by the condensation of alpha glucose.
cellulose is formed by the condensation of beta glucose.
describe the structure and function of starch
starch is a energy storage in plants.
1) hydrolysis of the glycosidic bond release glucose for respiration to release energy
2)has a compact helical shape which is good for storage
3)branched amplopectic- has lots of ends so has a large SA for enzymes to act on so glucose can release more rapidly for respiration.
4)starch is insoluble so no osmotic effect or doesn’t effect the water potential of the cell
describe the function and structure of glycogen
glycogen is an energy storage in animals and bacteria.
1)branched amplopectic- has more branches then starch. which allows it to have a large SA for enzymes to work on and release glucose for respiration rapidly.
2)has a compact helical shape wich give it a good storage.
3)insoluble so no osmotic effect
describe the function and structure of cellulose.
cellulose is in plant cells and are there for structral support.
1)have no branches and have a staright chain which allows cellulose molecules to get closer together.
2)many h bonds form between neighboring chains which makes it strong
3)cellulose chains grouped together are called microfibrils and microfibrils grouped together are called macrofinrils and macrofibrils grouped together are called cellulose fibre
3)in order for beta glucose to form 1,4 glycosidic bonds every other glucose molecule needs to rotate 180 degress.
test for protein
add food solution in test tube
and biuret reagent solution
if present lilac if not blue
test for starch
food solution in test tube
add iodine and potassium iodide.
if blue black its present if orange negative
test for lipids
unfiltered food solution in test tube
add same volume of ethonal and waer then shake
if whit cloydy emultion forms lipid is present
if clear no present
test for reducing sugers
food sample in test tube add benedict solution and boil for 5 mins
if orange brown its present
test for non reducing
boil with acid and neutrilise it, hydrolise the sucrose to break the glycosidic bond and remain fructose and glucose, then add benedics and boil if lilac present.
name the two groups of lipids
triglycerides and phospholipids.
how is a triglyceride made what bonds are involved
it is formed by the condensation of one molecule of glycerol and three molecules of fatty acids. a condensation between a glycerol and a fatty acids forms an ester bond
r groups can be saturated and unsaturated how can u tell
r groups that are saturated only contain single covalent bonds between the carbon atoms. unsaturated r groups contain at 1 double bond with the carbon atoms
describe phospholipids
one of the fatty acids in the triglycerol is substituted into a phosphate containing group