The hydrogen bonds form cross-links betweens chains next to each other, while each individual H bond is weak, many thousands of H bonds collectively make cellulose very strong

What are triglycerides?

They are a type of lipid

What does polar mean?

Molecules with have dipoles

What does non - polar mean?

Molecules which do not have dipoles

What does lipids contain

C,H and O

What is the structure of a lipid / triglycerides?

1 glycerol and 3 fatty acid chains

What in the fatty acid binds with the glycerol to form the ester bond.

The OH in the carboxyl group at the end of the hydrocarbon chain

What does esterification mean?

The formation of an ester bond between the hydroxyl group of the glycerol binds with the carboxyl group of the fatty acids. an example of condenstion reaction

What does the formation of one trigylceride release.

3 water molecles due to the 3 ester bonds

Explain these specific ester bonds.

So, the H2O is released so the H from glycerol and the OH from the 3 fatty acids are taken out / removed so the O from the glycerol is the only that stays and the O=c- stays and bonds to an ester linkage

4 function of triglycerides

Insulation, protection, buoyancy and energy storage

How does it do insulation

As part of the myelin sheath and as adipose tissue below the skin

How does it peform proteciton

Adipose tissue protects organs from mechanical damage

How does it perform buoyancy

Fat/adipose tissue is low density allowing animals to float

How does it perform energy storage

When oxidized, a lot of energy is released. Stored in large amounts.

Give 4 functions of protein, p1

Antibodies, have a centrol role in the defence against disease

Give 4 functions of protein, p2

Collagen, gives strength to connective tissues

Give 4 fucntions of protein, p3

Enzymes, global proteins which control metabolism

Give 4 functions of protein, p4

To help with blood clotting, many components of the complex reaction of blood clotting contains protein

How would we form a dipeptide

2 amino acids

Give the diagram of 2 amino acids bonding, what ttype of reaction is it

Another example of a condensation reaction.

Give the structure of the amino acid

Here

Give the parts of an amino acid molecule.

Amino group (containing the N and H's), the side chain (different for different amino acids), the carboxylic acid group (containing the double bond between c and o)

Give the condensation reaction of amino acids.

The H from an amine group combines with the OH from a carboxyl group to release water and link the 2 amino acids in a covalent bond

Where is glycogen found?

Mainly found in the following locations in the body: Liver cells Skeletal muscle cells small amounts in the brain

What is glycogen connected by?

By two glycosidic bonds: an alpha-1,4-glycosidic bond and an alpha-1,6-glycosidic bond

What are the monomers that make up glycogen

Straight chain regions of glycogen consist of glucose monomers held together by α-1,4 linkages, while the branching points of glycogen are held together by α-1,6 linkages.

What is glycogen do in the human body

Main storage form of glucose, which is energy

What type of polysaccharide is glycogen?

Multibranched polysaccharide. GLYCOGEN IS BRANCHED

Where is starch found

Green leaves (manufactured from excess glucose during photosynthesis) Seeds Storage organs (grains and tubers), Amyloplasts (organelles within plant cells that produce and store starch)

What are the bond that are found in starch.

Alpha 1-4 glycosidic bond and alpha 1-6 glycosidic bond

What type of structure is starch

Helix shaped structure

What does starch do?

Used to store energy for cell metabolism, it is packed in semi crystalline granules that can be stored in roots and seeds

What are the smaller polysaccharides that make up starch

Amylose and amylopectin

What type of chain is amylose.

Linear chain polymer.

What type of chain is amylopectin

Branched chain polymer

What is a primary structure?

Simple polypeptide chain with amino acid joined together by peptide bonds

In the secondary structure what shapes can form

A - helix shape or B pleated sheet

Why do the secondary protein structure form these shapes?

Due to the formation of hydrogen bonds between weak, negatively charged nitrogen and oxygen atoms and weak, positively charged hydrogen atoms.

What does an a - helix look like

Has hydrogen bonds

What does a beta pleated sheet look like?

Has hydrogen bonds

What does a tertiary protein structure fold into

A 3D structure

What bonds are in tertiary structure, pt 1

Disulfide bonds (a disulfide bridge) that form between cysteine amino acids

What bonds are in tertiary structure, pt 2

Ionic bonds that form between charged R groups, + and a - charge

What bonds are in tertiary structure, pt 3

Hydrogen bonds that form between R groups

What is a Quaternary structure

Several polypeptide chains held together by the same bonds found in the tertiary structure.

What do quaternary protein structures often contain

Prosthetic groups (non-proteins that attach to proteins and assist them and include metal ions, sugars, vitamins, methyl groups and phosphate groups)

Explain the dipolar water molecule

Although the molecule has no overall charge, the oxygen atoms have a slight negative charge, and hydrogen has slight positive ones. The water molecule has both positive and negative poles meaning that it is dipolar

Explain specific heat capacity

As water molecules are cohesive it takes more energy (heat) to seperate them then would be needed if they did not bond to one another. without its hydrogen bonding, water would be a gas. important for organisms that live in water, prevents against sudden temprature variations. helping to regulate temprature and avoid extrems.

Why would hydrogen bonding help water.

It allows water to have large, cohesive forces and these allow it to be pulled up through a tube, such as a xylem vessel

Expain the latent heat of evaporation.

Hydrogen bonding between water molecules means that it requiers a lot of energy to evaportate one gram of water. the energy is called latent heat of evaporation. water is described of having high latent heat of evaporation. a very effective means of cooling because body heat is used to evaporate water.

Explain solvent action

The dipolar nature of the water molecule means that other polar molecules and ions readily dissolve in water. As a result water is a very good solvent and wide range of substances dissolve in it.

What is solvent action good for

Transport (sugars in blood and phloem removal of water (ammonia, urea) secretions (digestive juices, tears)

Give features of globular protein

Metabolic functions irregular amino acid polypeptide chains folded into a spherical shape relative unstable structures

Explain the structure of globular proteins (p1)

It has quatenery structure of 4 polypeptide chain. 2 identical alpha - globin polypeptide of 141 amino acids each and 2 identical b - globin polypeptide of 146 amino acids each

Explain the structure of globular proteins (p2)

Each polypeptide is folded into a compact shape and all four are linked together to form an almost spherical haemoglobin molecule

Explain the structure of globular protiens (p3)

Amino acids with hydrophillic R groups in the molecule told to orient themselves to point outwards, this enables haemoglobin to be soluble and mix more readily with a water medium

Explain the structure of a globular proteins (p4)

Associated with each polypeptide chain is a haem group - which contains a fe 2+ ion, non protein groups such as a this are called prosthetic group

Explain the structure of a globular proteins (p5)

Each fe 2+ ion can combine with a single oxygen molecule, making a total of 4 o2 molecules that can be carried by a single haemoglobin molecule in humans

How does the tight helix structure of amylose help.

Makes the molecule more compact and therfore can be stored more efficiently as it takes up less space

How much of starch is amylopectin and how much of it is amylose

80% amylopectin, 20% amylose

How is starch suited from energy storage

Being insoluble, it does not diffuse out of cells, amylose is a helicla structure and is compact, so a lot can be stored in a small space

What are the reagents used in non reducing sugar test

Benedicts solutions, dilute hydrochloric acid, sodium, hydrogen carbonate

Positive results for non reducing sugars

Remains blue on first testing ; coloured precipitate obtained when tested again after hydrolysis

Concentration for reducing sugars and what colour of solution of precpitate

None = low, very low = green, low = yellow, medium = brown, high = red

General formula for monosaccarhdies

(CH2O)n where 'n' can be any number from 3 to 7.

Monosaccharides are classified according to the number of carbon atoms in each molecule:

Pentose sugars (5 carbon atoms), Hexose sugars (6 carbon atoms)

Features of fibrous protein

Repitivive regular sequences of amino acids polypeptide chains form long paraellel strands support and structural functions

Explain what collegen is

Builds strength between connective tissue, extremely strong and stable. very high tensile strength and so is able to withstand immense pulling forces without stretching. it can still bend around a join as it flexes during movment.

How is collagen made for its role. p1

Its primary structure is largely a repeat of the amino acids sequence glycine-proline-alanine, which forms an unbranched polypeptide chain collagen made up of 3 such poltypeptide chains wound in a triple helix that is held together by hydrogen bonds between the peptide bond NH of a glycine and a peptide c=o (carbonyl) group of amino acid in the adjacent polypeptide.

How is collagen made for its role p2

As every third amino acid is the relatively small and compact glycine molecule, the triple helix produced is very tighytly wound. larger amino acids would produce a more loosely wound, and therefore less strong, triple helix

How is collagen made for its role p3

The triple stranded molecules run parallel to others, and in most types of collagen these form even stronger units called fibrils, with fibrils forming collagen fibres

Explain the lock and key hypothesis

Enzymes are therefore specific in the reactions in the reactions that they catalayse. The shape of the substrate (key) is complemntary to the shape of the active site of the enzyme (lock). it attempts to explain the specificity of enzymes

Explain the induced fit hypothesis

Rather than being a rigid lock, the active site of the enzyme is flexible and changes its form slightly to fit the shape of the substrate. This means that the substrate fits better into the active site of the enzyme.

Give the details of the structure of enzyme

There are amino acids with hydrophillic R-groups facing to the outside of the molecule. This makes the enzyme soluble in the aqueous internal environment of the cell or in the extracellular fluids such as blood and tissue fluid and allows it to catalayse metabolic reactions.

What are enzymes

Globular proteins, spherical shape determined by their sequence of amino acids.

What do enzyme inhibitors do

Enzyme activity can be reduced or even stopped (some might say ‘inhibited’) temporarily, by a reversible inhibitor.

Explain competitive inhibitors

Competitive inhibitors have a similar shape to a substrate and so are able to fit into the active site, blocking the substrate from doing so.

Explain non-competitive inhibitors

Non-competitive inhibitors do not bind to the active site, but elsewhere on the enzyme (allosteric site). This however, alters the enzyme's shape and so the active site becomes deformed.

What is Vmax

Its the maximal reaction rate or velocity of an enzymatically catalysed reaction when the enzyme is saturated with its substrate.

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