Question

1. concerning proteins:

a. the protein monomer is: amino acid
b. how many amino acids are there? 20
c. draw and label a basic amino acid in the box to the right.
d. what part of the amino acid differentiates it from another? r group
e. what is the directionality of a protein?
f. what is the significance of the directionality in protein digestion?

1. concerning lipids:

a. list the different types of lipids (4):
b. what is the similar structure between the four?
c. what is significant about hydrocarbons found in lipids? (2):
d. what is unique about phospholipids?
e. what does amphipathic mean?
f. what is the difference between saturated and unsaturated fatty acids?
g. why do unsaturated fats bend?
h. why is margarine a solid though it originates from plants? (btw, butter is solid at room temperatures)

1. concerning carbohydrates:

a. carbohydrates give us: (2)
b. carbohydrate monomers are
c. what are the two types of glucose molecules indicated?
d. what determines directionality in carbohydrates?
review sheet for ap biology 042 - biological molecules
contributed by winnie litten — youtube - /mslittenbiology twitter-@mslittenbiology

Explanation:

12a. Proteins are polymers made of amino - acid monomers.
12b. There are 20 standard amino acids in proteins in most organisms.
12c. Cannot be provided in text - based format (requires drawing). A basic amino acid has an amino group ($-NH_2$), a carboxyl group ($-COOH$), a hydrogen atom, and an R - group. For example, lysine has a positively - charged R - group.
12d. The R - group is unique to each amino acid and gives it distinct chemical and physical properties.
12e. Proteins have a directionality from the N - terminus (amino - end) to the C - terminus (carboxyl - end).
12f. In protein digestion, enzymes work in a specific direction (usually from N - terminus to C - terminus), which affects the efficiency and products of digestion.
13a. The four types of lipids are fats (triglycerides), phospholipids, steroids, and waxes.
13b. All lipids are hydrophobic or amphipathic and contain carbon, hydrogen, and oxygen. Fats and phospholipids have a glycerol backbone.
13c. Hydrocarbons in lipids are significant because they are the source of high - energy storage (in fats) and contribute to the hydrophobic nature of lipids.
13d. Phospholipids are unique because they have a hydrophilic head (containing a phosphate group) and two hydrophobic tails (fatty - acid chains), making them amphipathic.
13e. Amphipathic means having both hydrophilic and hydrophobic regions. In the case of phospholipids, the phosphate - containing head is hydrophilic and the fatty - acid tails are hydrophobic.
13f. Saturated fatty acids have no double bonds between carbon atoms and are straight - chained. Unsaturated fatty acids have one or more double bonds, causing kinks in the chain.
13g. Unsaturated fats bend because the double bonds in their fatty - acid chains create kinks in the otherwise straight hydrocarbon chain.
13h. Margarine is a solid though it comes from plants because it is usually hydrogenated. Hydrogenation adds hydrogen atoms to the unsaturated fatty - acid chains, reducing double bonds and making the molecules more straight - chained and able to pack closely together, resulting in a solid state.
14a. Carbohydrates give us energy and can serve as structural components (e.g., cellulose in plant cell walls).
14b. Carbohydrate monomers are monosaccharides.
14c. The two types of glucose molecules are alpha - glucose and beta - glucose, which differ in the orientation of the hydroxyl group on carbon 1.
14d. The directionality in carbohydrates is determined by the orientation of the sugar molecules, specifically the position of the anomeric carbon and the glycosidic bonds formed between monosaccharides.

Answer:

12a. Amino acid
12b. 20
12c. (Drawing required, not provided in text)
12d. R - group
12e. N - terminus to C - terminus
12f. Enzyme action direction affects digestion efficiency and products
13a. Fats (triglycerides), phospholipids, steroids, waxes
13b. Hydrophobic/amphipathic, contain C, H, O; fats and phospholipids have glycerol backbone
13c. High - energy storage, hydrophobic nature
13d. Amphipathic with hydrophilic head and hydrophobic tails
13e. Having both hydrophilic and hydrophobic regions
13f. Saturated have no double bonds, unsaturated have double bonds
13g. Double bonds create kinks in fatty - acid chains
13h. Hydrogenation makes it more saturated and solid
14a. Energy, structural components
14b. Monosaccharides
14c. Alpha - glucose, beta - glucose
14d. Orientation of anomeric carbon and glycosidic bonds