Biochemistry - carbohydrates Flashcards
State the gastrointestinal conditions.
- Constipation
- Diarrhoea
- IBS
- Stomach ulcer
What are the common signs of IBS?
- Abdominal pain
- Constipation
- Diarrhoea
- Gas
- Bloating
- Fatigue
- Mucus in stools
- Trouble sleeping
What are the triggers for IBS?
- Food
- Alcohol
- Processed snacks
- Stress, anxiety
- Antibiotics
How do food that cause discomfort act in different ways? (IBS)
- Irritants to the bowel
- Being degraded/fermented into products which generate gases such as carbon dioxide
What are FODMAP foods?
Foods that contain high levels of sugars
- these are liable for fermentation in the lower GI tract
Which sugar undergoes fermentation?
- Glucose
What is meant by fermentation?
- The conversion of sugar (glucose) to various products (alcohol) - wine
- Produced by yeast or bacteria
Describe the structure of glucose.
- Six carbons
- Poly-alcohol
- Carbonyl (in this case and Aldehyde) group
- Carbonyl groups are very reactive
Why does the straight chain (Fischer) contain more energy than cyclic?
Because a aldehyde group has more potential /chemical energy.
What is the importance of the cyclic structure of glucose?
- They are less reactive which allows them to be stored in the leaf or mammalian cell
Which bond binds two sugars?
O-glycosidic bond
State the three disaccharides.
Lactose: galactose and glucose
Maltose: two unites of glucose
Sucrose: glucose and fructose
What are polysaccharides and provide examples?
- When several saccharides are joined together
- The three most abundant polysaccharides are starch, glycogen, and cellulose
Describe the structure of starch.
- Starch is formed from poly-glucose, and exists
as two polymers, amylose and amylopectin
State the clinical and pharmaceutical use of starch.
As an excipient - a disintegrating agent in tablets
State the use of starch as a binder in tablet formulations.
- Helps hold the active ingredients together, providing cohesion and forming a solid tablet
State the use of starch as a disintegrant in tablets.
- Helps tablets break down rapidly into smaller particles when in contact with moisture, facilitating the release of the active ingredients for absorption.
State the use of filler/diluent in the preparation of tablets.
- Provides bulk to the formulation and ensures that correct dosage of the active ingredient is achieved.
Describe the function of glycogen.
- Serves as a form of energy storage in animals
- Stored primarily in the cells of the liver and skeletal muscle
Describe the function of cellulose.
- Is the main substance in the wall of plant cells
- Helps plants to remain stiff and upright
- Humans cannot digest cellulose, but it is
important in the diet as fibres
State FODMAP issues with IBS
➢Only Mono-saccharides and Di-
Saccharides are fermentable
➢Starch needs to be broken down into its
smaller units
➢The gastrointestinal bacteria can ferment
these sugars
➢Resulting in large volumes of BOWEL
gases and with it bloating and discomfort
Describe fructose fermentation and how it contributes to IBS.
- Mannitol has a high osmotic value
- It attracts Gastro fluids towards its chemical structure
- This will create diarrhoea and loose stools
Describe the osmotic effect of mannitol.
Hydrogen bonds:
* Interaction forms between molecules
➢ Forms between [Oδ-] in mannitol and
[Hδ+] in water molecule
➢ Hydrogen bonds are 1/10 weaker
than covalent bonds but it improves
the solubility of the molecule in water
State other physiological values of carbohydrates.
- Monosaccharides are used in the metabolism of drugs
- In order that drugs be excreted via the kidney, they have to be water soluble
What is conjugation and where does it take place?
- Drugs in the body can be made more water soluble by having sugar molecule
attached to them - Takes part in the liver - liver cells- endoplasmic reticulum/enzmes
- Enzymes involved
What is the main sugar used in the conjugation of drugs in the human body?
- An oxidation product of glucose called glucuronic acid
- Glucuronic acid increases the number of OH groups and consequently the hydrogen bonding and water solubility
What is the function on morphine glucoronidation?
- Increases the number of OH groups/hydrogen bonding
- More water soluble
- Can be eliminated by the kidney
