B1.1 Carbohydrates, Lipids and Fats Flashcards
How many covalent bonds can carbon atoms form?
any combination of single or double bonds up to 4 bonds
Define, with an example, condensation reaction.
A condensation reaction is a chemical process where two molecules combine to form a larger molecule, with the release of a small molecule, such as water, ammonia, or methanol. For example, glucose and galactose monomers forming disaccharide lactose with a release of a water molecule.
Distinguish between condensation and hydrolysis reactions. Give an example of each.
Condensation involves the formation of a larger molecule with the release of water. An example of a condensation reaction is is the formation of lactose from monosacharides glucose and galactose.
Hydrolysis involves the breakdown of a larger molecule with the addition of water. An example of hydrolysis is the hydrolysis of sucrose. Water is added to break the glycosidic bond of sucrose into glucose and fructose
Explain how the structure of glycogen enables it to perform its function in animals?
DEDUCE why glucose iis stored in muscle and liver cells in the form of glycogen, and not as individul glucose molecules?
Glycogen is relatively insoluble, and has no osmotic effects. The presence of extensive branching in glycogen means it has a compact sructure which allows for more glucose molecules to be stpred within a smaller volume. The presence of many non-reducing ends due to the many branches allows for more rapid enzyme controlled hydrolysis of glycogen into glucose, to release stored glucose when there is an increase in energy demand.
Why do glycogen and starch make good storage compounds?
Glycogen and starch make good storage compounds because of their relative insolubility due to their large molecuar size. The relative ease of adding or removing alpha glucose monomers by condensation and hydrolysis to build or to mobilise energy stores.
Identify the features of cellulose molecule that account for its strength
Compare and contrast the structure and function of starch, glycogen and cellulose.
Outline the roles of monosaccharides, disaccharides and polysaccharides in animals and plants. Use an example of each.
Monosaccharides are monomers of carbohydrates, they are the main respiratory substrate for cells. for instance, glucose is used in both animal and cell respiration to produce ATP. For instance, our bodies trabsport simple sugars (monosaccharides) in the blood. In cells and organisms, glucose acts as the bulding block for many larger molecules, such as cellulose, and starch in plants and glycogen in animals.
Disaccharides are often used to transport sugars. They can be broken down into monosaccharides for energy. for instance sucrose. Sucrose is transported by the phloem to provide energy to various tissues. And in animals, it is broken down into monosaccharides for energy.
polymers are used to store compounds and are used for support. For instance, polysaccharide starch is insoluble and used to store carbohydrates in plants such as amylose and amylopectin. The alpha 1-4 and alhs 1-6 of the alpha glucose moleculre in starch assists in branching and coiling, allowing to store more energy per volume. Additionally, in animals. glycogen is found in liver and muscle tissues and can be mobilized easily when energy is needed. Lastly, cellulose is made from beta glucose molecules in unbrnches chains as support for the cell wall. The fibrils also make it flexible, allowing expansion when water enters the plant cell.
Distinguish between antigen and antibody
Antigens are gylcoproteins while antiodies are protein. Furthermore, antigens are found both within and outside of the body (e.g. ABO blood group) whul antobodoe are exclusively found within the bidy, prouced. y lymphocytes, a group of white blood cells. Lastly, while an antigen is a substance that induces an immune response an antibody has proteins taht recognise and bind tp antigens.
Describe the structure and function of starch in plants.
a. «starch» is a polysaccharide/is composed of glucose molecules;
b. contains amylose which is a linear/helical molecule;
c. contains amylopectin which is a branched molecule;
Function:
d. storage of glucose/energy in plants;
Distinguish between lipids and carbohydrates as energy stores
Energy density:
Lipids: Store twice as much energy due to their long hydrocarbon chains. They are efficient long-term energy stores.
Carbohydrates: Store less energy per gram (~4 kcal/g). They are used for short-term energy storage and quick release.
Storage form:
Storage form:
Lipids: Stored primarily as triglycerides in adipose tissue. They are hydrophobic, so they don’t require water for storage, making them more compact.
Carbohydrates: Stored as glycogen in the liver and muscles. Glycogen is hydrophilic and binds to water, making it bulkier and less energy-dense per unit of mass.
Energy released
Lipids: Provide slow-release energy because they must be broken down into fatty acids and glycerol, which are metabolized via beta-oxidation and other processes.
Carbohydrates: Provide rapid energy as glycogen can be quickly converted to glucose for immediate use in cellular respiration.
List two properties of phospholipids
Amphipathic nature: Phospholipids have both hydrophobic (water-repelling) tails and hydrophilic (water-attracting) heads. This allows them to form bilayers in water, which is a fundamental structure of cell membranes.
Fluidity: The fatty acid chains in the phospholipid tails can be either saturated or unsaturated, affecting the membrane’s fluidity. Unsaturated fatty acids with double bonds create kinks, preventing the phospholipids from packing too tightly and increasing membrane fluidity.
What is the difference between D and L glucose
If OH group is on the bottom right, the sugar is D. If the OH group is at teh bottom left, the sugar is L.
Distinguish between alpha- and beta- glucose monomers.
The difference between alpha / ɑ and beta / β glucose is that in the alpha glucose, hydrogen of the first carbon is above the ring whereas in the beta glucose, the hydrogen of the first carbon is below the ring.
