Carbohydrates Flashcards
What are Carbohydrates components of?
- Water and Carbon
What molecules are carbohydrates made of?
- Hydrogen, Oxygen + Carbon
- Ratio 1:2:1 - CH20
Read
CARBOHYDRATES ARE
- Main source of Energy for all living organisms –Glucose.
- Serve as structural components such as DNA – Ribose, Cell wall made up of cellulose.
- The simplest carbohydrates are sugar units also called saccharides.
What are the 4 types of Carbohydrates?
- Monosaccharides (1 saccharide)
- Disaccharides (2 saccharide)
- Oligosaccharide (3 or more saccharides)
- Polysaccharide ( >10 saccharides)
What are the simplest carbohydrates/ sugar units also called
- Saccharides also called sugar units.
What are Monosaccharides?
give examples
- Simplest carbohydrates + can’t be hydrolysed to
smaller carbs. - End in -ose
- E.g. Glucose, Galactose, Fructose
What is the functional group of a monosaccharide?
- Carbonyl Group
- Chemically organic functional group composed of a carbon atom double-bonded to an oxygen atom → [C=O]
What are the 2 Carbonyl groups for a Monosaccharide?
- Aldehyde ( C=O bonded to at least one Hydrogen) always in C chain.
- Ketone ( C=O bonded to 2 Carbons) always w/in C chain.
What do Aldehyde’s and Ketones turn to when they’re monosaccharides.
- Aldoses
- Ketoses
Read
- Most common monosaccharide: 3-7 carbons (unbranched)
- No. of C atoms given by prefix: tri-, tetr-, pent-, hex-, hept-
- No. of carbons Generic Name: 3 Triose
4 Tetroses
5 Pentoses
6 Hexoses
7 Heptoses
Read
- A 3C triose sugar with an aldehyde group = aldotriose sugar
- A 4C tetrose sugar with an aldehyde group = aldotetrose sugar
- A 5C pentose sugar with an aldehyde group = aldopentose sugar
- A 6C hexose sugar with an aldehyde group = aldohexose sugar
- A 7C heptose sugar with an aldehyde group = aldohepose sugar
- A 3C triose sugar with an ketone group = ketotriose sugar
- A 4C tetrose sugar with an ketone group = ketotetrose sugar
- A 5C pentose sugar with an ketone group = ketopentose sugar
- A 6C hexose sugar with an ketone group = ketohexase
- A 7C heptose sugar with an ketone group = ketoheptose sugar
What are Chiral Centers?
see pics slide 11 +12 + 13 +14
- Chiral centers are tetrahedral atoms (usually C) that have 4 diff substituents.
- Molecules with “n” chiral centers have 2n stereoisomers.
- E.g. Glyceraldehyde: 1 chiral center
What are Isomers?
- 2 compounds that have the same molecular formula, but have diff structural formulas.
Read
- Ribose & Ribulose are isomers that differ by the location of the carbonyl group (C=O).
- In ribose the C=O belongs to an aldehyde
- In ribulose the C=O belongs to a ketone
- Ribose is classified as an aldose, Ribulose is a ketose
- Similarly Glucose & Fructose are isomers where glucose is an aldose & fructose is a ketose.
What is the main source of energy for cells or humans?
- Glucose ( C6 H12 06)
Read
- Look at slides 16 - 19
How are monosaccharides attached to each other?
- By covalent bonds called Glycosidic bonds by a condensation rxn.
Where are Glycosidic bonds formed?
- Between C 1 of a monosaccharide & a hydroxyl (OH) carried by a C atom in a diff monosaccharide molecule.
Give an example of a Disaccharide?
- Maltose (2 glucose molecules covalently bind by a glycosidic bond.
- Lactose (Galactose + Glucose)
- Sucrose (Glucose + Fructose)
Oligosaccharide example?
- Raffinose
- Stachyose
What are Polysaccharides also called?
- Glycans
Function of a Polysaccharide?
- Energy storage (glycogen in animal & starch in plant cells)
- Structural support (cellulose in plant cell wall)
Examples of Polysaccharides?
- Glycogen
- Starch
- Cellulose
- Chitin
Use of monosaccharides in animals?
- Glucose is carried by the blood to transport energy to cells throughout the body.
Use of monosaccharide in plants?
- Fructose
= sweet taste
= attracts animals
= disperse seeds
Use of disaccharide in animals?
- Glycogen = short-term energy store in liver & in muscles.
Use of disaccharide in plants?
- Sucrose – carried by Phloem to transport energy to cells
through the plant.
Use of Polysaccharides in animals?
- Glycogen = short-term energy store in liver & in muscles
Use of Polysaccharides in plants?
- Cellulose = strong fibers, used to construct plant cell wall.
Read
- Major source of energy which is available immediately as glucose.
- When excess Carbohydrate is available it can be stored as glycogen in the liver & muscle cells of animals & starch in plants.
- Forms Structural Tissue in - Plants - cellulose
- Animals – proteoglycans: teeth, cartilage
- Bacteria - cell wall - Found in the plasma membrane linked to lipids – glycolipids & play a role in structural integrity of the cell.
- Found in the plasma membrane linked to proteins – glycoproteins & play a role in cell recognition.
- Ribose sugar is important in the formation of DNA & RNA.
- Proteins Sparing Action – when Carbohydrates are not sufficient in our body, proteins are broken down to fulfil the requirement of Carbohydrate.
- Helps prevent Ketosis – in the absence of adequate Carbohydrate, large amounts of ketone bodies are produced in the blood. This increases the blood acidity. In severe cases this can lead to coma/death.
- Provides Fibre – creates soft bulky stool that moves quickly through the large intestine.
