Biology - Biomolecules

SVT Bio Y12

monosacharide

a single sugar unit

disacharide

two sugar units/dimer

polysacharide

many sugar units

three examples of monosacharides

glucose, fructose, galactose

3 examples of disacharides

maltose, sucrose, lactose

3 examples of polysacharides

starch, glycogen, cellulose

what is the bond joining the disacharide

glycocidic bond

what reaction forms disacharides, and polysacharides

condensation reaction

release of H20

condensation

maltose

glucose+glucose

sucrose

glucose+fructose

lactose

glucose+galactose

why does the second B-glucose have to flip when two B-glucose molecules are joined by condensation

• β-glucose has its –OH group on carbon 1 (C1) pointing upward.

• To form a β-1,4 glycosidic bond, the C1 of one β-glucose must link to the –OH on carbon 4 (C4) of another β-glucose.

what are the monomers of starch?

amylose and amylopectin

explain the bonds between the monomers in starch

Glycosidic bond 1-4 (linear), 1-6 branch points in amylopectin

location of starch

inside plant cells, roots, seeds

structure of starch

linear branched coiled compact structure

how does the structure of starch lead to it’s function

Long chain bonded by a- glycosidic bond alpha 1-4 giving it a coiled structure, as well as alpha 1-6 glycosidic bonds resulting in the branch structure (amylopectin)

what is the function of starch

energy storage in the cell.

what are the monomers of cellulose

B-Glucose molecules

what is the function of cellulose

protecting plant cell.

location of cellulose

Plant cell wall

What is the structure of cellulose

1-4 B-glucose ratio forming straight chains, each B-glucose is rotated 180degrees relative to previous to form straight structure creating strong H-bonds.

what are the bonds forming cellulose called

H-bonds, b-1-4 glycosidic bond

how does the structure of cellulose lead to it’s function

The B-glucose run parallel to one another and the multitude of H-Bonds create microfibril which become a part of macrofibril giving high tension and rigidity that make up the cell wall of the plant (therefore protecting it)

what are the monomers of glycogen

a-glucose

what are the bonds that make up glycogen called

1-4 glycosidic bonds, yet more 1-6 glycosidic bonds

Where is Glycogen located

Liver

What is the structure of glycogen

Contains 1-4 glycosidic bonds, yet more 1-6 glycosidic bonds which results in a highly branched structure

what would happen to the DE value if sucrose was heated with dilute HCl in a chemical reaction

the hydrolisis reaction would produce glucose and fructose (both reducing sugars) which would increase the DE value.

how does the structure of glycogen lead to it’s function

The highly branched structure is more compact than starch as a result of having more a-1-6 glycosidic bonds allows for energy to be broken down faster due to the high amount of ends that enzymes can release glucose quickly (suiting rapid energy release)

why is starch coiled (in the case of amylose)

makes molecule compact for storage of energy in the cell.

why is starch branched (in the case of amylopectin)

more ends for fast breakdown of energy/ more enzyme action allowed

starch CANNOT

• dissolve in water

• cross the cell membrane

polymers of glucose

can be rapidly broken down to provide glucose for respiration through hydrolisis (splitting of H20)

what is a lipid

a hydrophobic polar molecule that is soluble in non polar solvents - eg: butter, oil, waxes.

Lipid Function

• stores energy

• contributes to flexible membranes in the plasma membrane

• long lasting energy source

• retain heat under the skin through insulation.

Saturated Fatty Acid

hydrocarbon chain has only single bonds (solid)

Unsaturated Fatty Acid

C=C double bonds, at least one double bond, loses 2 Hydrogen for every double bond present (liquid).

what makes tryglicerides

3OH groups and 3 Fatty acids

what is the reaction triglycerides are created through called

dehydration synthesis

what is the waste product in the formation of triglycerides

3H20 - 1 hydrogen from each OH group, and 1 HO from each fatty acid group

what do phospholipids contain

CHONP

phospholipids

make up the cell membrane

the outside of the cell is

hydrophilic (polar)

the inside of the cell is

hydrophobic (non polar)

proteins are made up of 

CHON

carbohydrates and lipids are mainly made up of

CHO (phospholipids)

3 functions of proteins:

making up enzymes, forming antibodies, building muscle

monomers of proteins

amino acids

how is a dipeptide formed

through the joining of the carboxyl and amino acids by a condensation reaction.

primary structure of proteins

a sequence of amino acids making up a polypeptide chain determining the shape of the protein with limitless ammounts of combinations.

what is the bond in the primary structure of proteins maintaining structure called

peptide bond

secondary structure of proteins

the folding or coiling of the primary structure’s polypeptide chain into shapes like a-helice and b- pleated sheets.

alpha-helices

• very stable

• tightly coiled spiral

how are a-helices formed?

the backbone of the polypeptide chain coils and are stabilized by hydrogen bonds

tertiary structure of proteins

• folded polypeptide chain due to R group

• coiled 3D shape

• hydrophilic R group on outside

bonds in tertiary structures

• ionic bonds

• disulfide bonds

• hydrogen bonds

quaternary structue

• multiple polypeptide chains (2 or more)

• H-bonds and R group interactions occur based on the amino acids in the proteins

bonds in quaternary structure

H - bonds