carbohydrates

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Kaiden a

Cards (36)

What are the three roles of carbohydrates in organisms?
Energy source for respiration (e.g., glucose)
Energy store (e.g., starch, glycogen)
Structural role (e.g., cellulose in plant cell walls)
What is a monosaccharide?
A simple sugar that cannot be broken down into simpler sugars by hydrolysis.
How are monosaccharides classified?
By the number of carbon atoms they contain.
What is ribose?
A monosaccharide formed of five carbon atoms, making it a pentose sugar.
What are the key characteristics of carbohydrates?
Composed of C, H, and O in the ratio Cx(H2O)x
Names usually end in “-ose”
Three roles: energy source, energy store, structural role
What is the ratio of hydrogen to oxygen in carbohydrates?
For every carbon atom, there are two hydrogen atoms and one oxygen atom.
What is the significance of the suffix “-ose” in carbohydrate names?
It indicates that the compound is a sugar or carbohydrate.
How do the structures of alpha-glucose and beta-glucose affect their functions?
Alpha-glucose forms starch or glycogen, while beta-glucose forms cellulose due to their bonding differences.
What is a monosaccharide?
A simple sugar that cannot be broken down into simpler sugars by hydrolysis
Give two examples of monosaccharides.
Glucose and fructose
What is a disaccharide?
A sugar composed of two monosaccharides
Name two examples of disaccharides.
Sucrose and lactose
How is a disaccharide formed from monosaccharides?
Through a condensation reaction that forms a covalent bond
What type of bond is formed between monosaccharides in a disaccharide?
A glycosidic bond
What happens during hydrolysis of a disaccharide?
A water molecule is added to break the glycosidic bond
What is starch composed of?
Two types of molecules: amylose and amylopectin
Where is starch found in plants?
In chloroplasts and membrane-bound starch grains
Is starch soluble in water?
No, starch is insoluble in water
What is the structure of amylose?
A linear molecule made of poly-(1,4) alpha-glucose
How does amylose's structure affect its shape?
It curls up into a helix held by hydrogen bonds
What is the difference between amylopectin and amylose?
Amylopectin has branches, while amylose is linear
Why can amylopectin be hydrolyzed more quickly than amylose?
Because it has more ends for enzyme action
What color does iodine turn when added to starch?
Blue-black
Why does iodine turn blue-black in the presence of starch?
Because iodine molecules become fixed in the center of the amylose helix
What is glycogen and where is it found?
Glycogen is a storage polymer in animal cells, mainly found in muscle and liver cells
How does the structure of glycogen compare to amylopectin?
Glycogen is more highly branched than amylopectin
What is cellulose and where is it found?
Cellulose is a structural component of plant cell walls
What type of glucose forms cellulose?
Beta-glucose
How does the structure of cellulose differ from starch and glycogen?
Cellulose forms straight, unbranched chains, while starch and glycogen are branched
What is required to digest cellulose?
A specific cellulase enzyme
Why can't humans digest cellulose?
Because humans lack the cellulase enzyme
What is dietary fiber?
Cellulose, which humans cannot digest
How are cellulose microfibrils formed?
By linking hundreds of cellulose chains together with hydrogen bonds
What gives strength to plant cell walls?
Cellulose microfibrils formed from linked chains
How does the bonding in beta-glucose affect cellulose structure?
Every other glucose molecule must be rotated 180º to form a 1,4 bond
What is the significance of the 1,4 glycosidic bond in cellulose?
It allows for the formation of strong, unbranched chains