Carbohydrates and lipids Flashcards
What is a monomer?
A monomer is a small unit that can join together to form polymers
What is a polymer?
A polymer is monomer joined together to form a chain of monomers
What is a monosaccharide?
A monosaccharide is a sugar unit that can join together to others to form polysaccharides and disaccharides
What are some examples of monosaccharides?
Glucose fructose and galactose are all examples of monosaccharides
What are some examples of disaccharides?
Lactose sucrose and maltose are all examples of disaccharides
How do these monosaccharides join to form disaccharides?
The monosaccharides undergo condensation reactions to form disaccharides. The condensation reactions consist of the removal of water to form a glycosidic bond between the two molecules for example 2 alpha glucose molecules for Maltose
How do disaccharides split to form monosaccharides?
They undergo hydrolysis reactions, which is the insertion of a water molecule to break the glycosidic bond and form two monosaccharides
What are the two isomers of glucose?
Alpha glucose and beta glucose, we can distinguish between these because in alpha glucose the hydroxyl group is below and in beta glucose the hydroxyl group is above
What are the two polysaccharides?
Cellulose which is made from beta and starch which is made from Alpha
What makes starch a good storage molecule?
It is very big so it can’t cross the cell membrane. It’s also contains two monomers which are amylose and amylopectin. Amylose is very coiled so it’s very compact and amylopectin is very brunched so it can be easily hydrolysed to release glucose for respiration. Starch is also very insoluble.
What are the features of cellulose?
The beta molecules in cells are flipped to 180° to form straight chains of beta glucose. There are lots of hydrogen bonds to form microfibrils which provides strength and support to the cellular structure.
What are more examples of monosaccharides?
Amino acids and nucleotides
What type of bonds do starch and cellulose have?
The starch monomer amylose has one to 4 glycolytic bonds and amylopectin has 126 glycolic bonds and since starch is a polymer of alpha glucose. It provides more glucose for respiration. and it’s usually found in liver or muscle cells.
What is the reducing sugars test?
Add excess Benedict solution to our test solution then we have to boil the mixture and then if a reducing sugar is present, the solution will change from blue to brick red or yellow or green
What is the non-reducing sugar test and which sugar is a non-reducing sugar?
Sucrose is the only non-reducing sugar
First, we had Benedict‘s region and we heat if it’s still blue we do the following steps
Add hydrochloric acid and heat to break the glycosidic bond
Then we neutralise the acid with sodium hydroxide then we add Benedict’s regent and boil. If it turns red then a non-reducing sugar was initially present.
What is the test for starch?
Iodine dissolved in potassium iodide solution reacts with starch resulting equal change from orange brown to blue black
What are the two groups of lipids?
Triglycerides and phospholipids
What do triglycerides and phospholipids contain?
Triglycerides contain three fatty acids and one glycerol molecule whereas phospholipids contain two fatty acids, one glycerol molecule and one phosphate group
What charges do both triglyceride and phospholipids have
Triglycerides are fully nonpolar whereas phospholipids have polar and nonpolar regions
What are the features on phospholipids?
Phospholipids have hydrophilic heads which face outwards and hydrophobic tales which face inward creating a bilayer hydrophilic means that it’s attracted to water and hydrophobic means that it’s not attracted to water they are typically found in cell membranes
What are the two types of fatty acids?
A fatty acid is a long chain of hydrocarbon with a carboxyl group at one end they can either be saturated or unsaturated. Saturated fatty acid are saturated with hydrogen and only have a carbon carbon single bond. Unsaturated fatty acid have a lot less hydrogen and they have a carbon carbon double bond and they have a kink in the middle of the chain
What does a molecule of glycerol contain?
It consists of three hydroxyl groups and each one of these can undergo a condensation reaction to join to a fatty acid or phosphate
What happens when a glycerol molecule bonds with a phosphate group or a fatty acid?
It’s undergoes a condensation reaction and three water molecules are removed which forms an ester bond.
Provide more details on phospholipids
The hydrophilic heads face outwards towards the tissue fluid and watercytoplas, and hydrophobic fatty acid tales facing inwards making a water tight layer. The heads are attracted to the aqueous environment. Membranes which contain phospholipid with a high proportion of unsaturated fatty acids are more fluid and permeable than those with a high proportion of saturated fatty acid. This is because the double bond between carbons causes the fatty acid chain to bend pushing the adjacent phospholipid away from it, this makes them less tightly packed together
