Definitions

Question 1

What are vitamers?

Answer 1

Different molecular structures of vitamins i.e. Vitamin A has the vitamers of Retinol, retinal and retinoic acid.

Question 2

What are vitamins?
What can they not do? (2)
Two examples of being precursors

Answer 2

Organic compounds required by the body in small amounts for normal metabolic functions
- cannot be manufactured by the body, thus are essential
- cannot be converted into energy but some are co-factors in the process of energy production
Example: Vit b5 is needed for the synthesis of coenzyme A (crucial for Krebs cycle
Vit B6 is needed in the transfer of amino groups (critical to amino acid metabolism)
Most Vit b come from plants; most fat soluable come from animal sources.

Question 3

What are Probiotics?

Answer 3

Probiotics are live microorganisms (in most cases bacteria) that help to keep the digestive system healthy by reducing the growth of harmful gut microbes and boosting the number and variety of ‘friendly’ but microbes.

Maintain tight junction integrity (tight junctions are between each of the cells in the intestinal wall, need to be tight yet flexible to let nutrients and other molecules though the intestinal wall and into the blood stream).

Increase the qualify of the modus layer that protects the intestinal wall and enhances the production of molecules called defensins (type of anti-microbial regulator that keeps nasty bugs under control).

Modulate the immune system (turning it up or down)

Question 4

Examples and benefits of short chained fatty acids

Answer 4

Butyrate, acetate and propionate
Waxy molecules that help lower the local pH in the gut, making it less hospitable environment for disease carrying bacteria (e.g. clostridium difficile) to adhere to the intestinal wall and reproduce there.

Question 5

What do high levels of zonulin indicate?

Answer 5

Measured via stool test, high levels are seen as a sign of intestinal permeability or leaky gut, which is a symptom of overall disruption of the gut.

Question 6

What are electrolytes? And 3 functions

Answer 6

Any ionic compound i.e. salt, that has been dissolved in water.
Therefore there are positive and negative ions i.e. Sodium (NA+), Chloride (CL-), Potassium (K+), Magnesium (MG++), Calcium (CA++) Phosphate (HP04-) and Bicarbonate (HCO3-)
Main ones are salt, potassium and chloride.

Nerve and muscle function;
They exert osmotic pressure important for water balance i.e hydrate the body
Some play an important role in acid-base balance
Help rebuild damaged tissue ?? (Check this)

Question 7

What is an acid? What is a base?

Answer 7

A substance that releases a high concentration of H+ ions is an acid.

A base is a substance that binds to the H+ and mops them up and creates a lot OH-.

If you put an acid and a base together, they react chemically to form a salt plus water.

HCL (salt) plus KOH (Potassium Hydroxide) = KCl plus H2O

Question 8

Buffer systems

Answer 8

Like little banks, if there is too much acid they mop it up, too little they release it.

Hydrogen + bicarbonate ion = carbonic acid
Or
Sodium hydroxide plus carbonic acid = sodium bicarbonate plus water

Back up plan = breathe out to get rid of CO2 naturally lowers acidity
and the kidneys can get rid of H+ ions via the urine.

Question 9

What are free radicals?

Answer 9

A free radical is a molecule or compound that has an unpaired electron; it will promote oxidation (stealing electrons from other molecules) causing a chain of damage until it comes across something big enough that can afford to loose electrons. With humans that could be DNA which will then lead to issues further down the road i.e. cancerous changes; or antioxidants found in fruit and veg.

Question 10

What are anti-oxidants?

Answer 10

Chemicals that can give up electrons without being damaged themselves i.e. Vitamin C that has a cloud of electrons. They can also recycle themselves by interacting with other antioxidants (i.e. Vit C and Vit E) that s why it’s important to ingest a mixture of different anti-oxidants.

Question 11

What are isomers and epimers?

Answer 11

An isomer is anything that has the same chemical formula but is arranged in a slightly different structure i.e. glucose, fructose, galactose and mannose are all isomers of each other’s.

If the difference is only on one carbon a tome they are also known as epimers i.e. glucose and galactose.

Question 12

What is chemistry?

Answer 12

Chemistry is the study of matter and all the interactions that take place within matter

Question 13

What is matter? And what are atoms?

Answer 13

Matter is everything around us that occupies space and has mass. Atoms are small particles of matter and are made up of electrons, protons and neutrons.

Question 14

Difference between atomic and mass number of an atom

Answer 14

Atomic number = number of protons and electrons

Mass Number = number of protons and neutrons in the nucleus

Question 15

Isotopes

• definition
• relationship to radiation
• applications in medicine

Answer 15

Isotopes are atoms of the same element which have different number of neutrons = does not affect the chemical activity as neutrons have no charge but it does change the mass;

Some (but not all) have such an imbalance of protons and neutrons that the atom becomes unstable. This is the cause of radioactivity. The unstable atom needs to get rid of energy to become stable by:

• alpha decay - ejecting protons and neutrons from the nucleus
• beta decay - splitting neutrons into protons and high energy electrons can be ejected
• gamma decay - emitting energy as gamma rays

Diagnostic techniques to scrutinise physiological process
Radiotherapy uses gamma rays to target rapidly dividing cells
Breath test for H Pylori uses urea labelled with either radioactive carbon-14 or non-radio active carbon-13.

Question 16

Why do some atoms have more electron pulling power?

Answer 16

Elements with lots of protons compared to the number of electron shells i.e. a strong positive centre which isn’t shielded by a massive cloud of negative electrons have higher electro negativity. They tend to pull shared electrons towards themselves.
This results in the negative electron cloud spending more time at one place on the molecule creating opposite charges at each end of the Bon making it act like a magnet.
Most electronegative elements are F, C, O and N.

Question 17

What’s an element?

Answer 17

An element is a substance made up of just one type of atom so it cannot be split into simpler substances.
There are 26 different elements normally in the human body.
4 x major elements - carbon, hydrogen, oxygen and nitrogen account for 96% of the human body.

Question 18

What is a chemical reaction?

Answer 18

Chemical reactions occur when new bonds are formed or old bonds are broken between different molecules.
And involves the transfer of energy to potential (stored) energy, kinetic energy or heat; either endothermic (takes in heat to use for energy) or exothermic that releases heat into the environment.
Starting materials are reactants and the end molecules are products.
Reactions are written in formula and they must always balance the electrons on each side i.e. A+B=AB

Question 19

What is activation energy?

Answer 19

The minimum energy that is required for a chemical reaction to occur. Reliant on

The correct temperature
High concentration of reactants
Changes in pressure that can change the speed of reactions
Increasing pressure forces molecules closer together

Question 20

What is hydrolysis? And what is the opposite

Answer 20

Hydrolysis is when water is the medium that breaks down the molecule in to smaller pieces.

The opposite is when water is the waste product of a reaction, known as dehydration synthesis or condensation reaction, this normally when larger molecules are made.

Question 21

What are prostaglandins?

Answer 21

Hormone like substances responsible for many functions at cellular level and regulate many body processes

Question 22

Difference between endothermic and exothermic reactions

Answer 22

An endothermic reaction is one that takes in heat to use for energy for example photosynthesis where plants use sunlight to produce food and energy; boiling water, melting ice cubes, cooking an egg.

An exothermic reaction is one that release heat into the environment i.e. a fever.

Question 23

What is metabolism?

Answer 23

Chemical processes that occur within the body in order to maintain life. Categorised into catabolism = breakdown of molecules to obtain energy and anabolism = synthesis of all compounds needed by the cells.