Biological Molecules Flashcards
What is the bond between two monosaccharides?
Glycosidic bonds
What is maltose made from?
Two glucose molecules
Name four monosaccharides
Alpha Glucose, Beta Glucose, Galactose, Fructose
What is sucrose made from?
Glucose and Fructose
What is lactose made from?
Glucose and galactose
How are disaccharides and polysaccharides formed?
Condensation reaction - form a water molecule
What are glycogen and starch made of?
a-glucose
What is cellulose formed from?
B-glucose
What is the main role of starch and how?
Energy storage
- Insoluble, doesn’t affect water potential
- Large + Insoluble, does not diffuse out of cells
- Compact
- When hydrolyzed, it forms a-glucose, which can be easily transported and used in respiration
- Branched form has many ends, each of which can be acted on by enzymes simultaneously so that glucose can be released rapidly
What is the function of glycogen?
Similar structure to starch.
Shorter chains but more highly branched.
Stored in muscles and in the liver.
Mass of storage is small as fat is the main storage molecule in animals.
How is glycogens structure related to it’s function?
- Insoluble, does not tend to draw water into cells or diffuse out of cells.
- Compact
- More branched to suit the high metabolic rate of animals.
How is the structure of cellulose beneficial?
Straight unbranched chains that are parallel to each other allow the hydrogen bonds present to form cross-linkages, making them strong. This is due to the B-glucose involved.
What is a reducing sugar?
A sugar that can donate electrons to another chemical/reduce.
e.g: Monosaccharides and some disaccharides
What is the test for reducing sugars?
-Add 2cm of the food sample to the test tube, must be in liquid form.
- Add an equal amount of Benedict’s reagent.
- Heat the mixture in a water bath for five minutes.
Result: Orange-brown colour
What is the structure of an amino acid?
R
l
H2N-C-COOH
l
H
