Chapter 5 Study Guide PDF

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General Biology 1

I)

Ch 5 (Macro[bio]molecules) Study Guide Questions

Carbohydrates & Sugars 1) What are the four major classes of macro/biomolecules? 1. 2. 3. 4.

Lipids Carbohydrates Proteins Nucleic Acids

2) What is a polymer? A monomer? i. Explain how the two are related by the processes of dehydration and hydrolysis. Polymer- A long molecule consisting of many similar building blocks Monomer- Small building-block molecules Through the process of dehydration, two monomers are connected by a reaction in which two molecules are covalently bonded to each other, with the loss of a water molecule. As this process is repeated one by one, a polymer is made. Through the process of hydrolysis, polymers are disassembled to monomers. That is the bond between monomers is broken by the addidtion of a water molecule, with a hydrogen from water attaching to one monomer and the hydroxyl group attaching to the other. 3) Name the main categories of carbohydrates and how they relate to each other structurally. i.

ii. iii.

Monosaccharides-(Simple sugars)- C6H12O6- Contains a carbonyl (CO) group as well as multiple hydroxyl (-OH) groups. Depending on the location of the carbonyl group, a sugar is either an aldose (aldehyde sugar) or a ketose (ketone sugar). Linear form, but can also form rings Disaccharide- (double sugars)- 2 monosaccharides joined chemically through dehydration. C12H22O11. Maltose (beer) Lactose (milk) Sucrose (table sugar) Polysaccharides-(many sugars)- a long chain of monosaccharides joined through a glycosidic linkage (dehydration). These can either be storage polys like starches or structural polys like cellulose.

4) Explain how the same type of carbohydrate component can be linked together to form either energy storage products or structural support material, using starch and cellulose as examples. The architecture and function of a polysaccharide are determined by its sugar monomers and by the positions of its glycosidic linkages. Starches (storage poly) Cellulose (structural poly)

General Biology 1

Ch 5 (Macro[bio]molecules) Study Guide Questions

5) How do starch, glycogen, and cellulose each differ in structure and function? In what organisms does each occur? Starch : an energy storage in plants; Helical chains Glycogen : energy storage in animals (Highly branched) Cellulose : cell wall structure in plants; linear, linked chains of glucose; hydrogen bonds hold chains together 6) Describe the important chemical properties of lipids in relation to their energy content (versus protein and carbohydrate) and solubility characteristics. Unlike the other macromolecules, lips are not soluble in water and they don’t form long sequences made up of similar or repeating smaller units; lipids are triglycerides, consisting of three fatty acids attached to a glycerol Fat stores twice the energy (9kcal/g) of Protein and carbs (4 kcal/g) 7) What is a fat (triglyceride) composed of? How do saturated fats and unsaturated fats differ, and how does this explain their physical state at room temperature? Structure: Glycerol- 3 hydroxyl groups; 3 fatty acids- hydrocarbons and carboxylic acid ends Fatty acids that are saturated (single bonds ) with as many hydrogen atoms as it can hold is a solid at room temperature and unsaturated fatty acids (double bonds) are liquid. Because of the single bond it forms more of a linear shape, making less movement (solid) while unsaturated is able to move more (liquid 8) What are steroids using the cholesterol molecule as an example and give some examples of its modification into specially functioning molecules? Steroids are lipids characterized by a carbon skeleton consisting of four fused rings. Cholesterol is a type of steroid that is a common component of animal cell membranes and is also the precursor from which other steroids, such as the vertebrate sex hormones, are synthesized. Examples: sex hormones for muscles synthesis and stress hormones like cortisol that stop pain. 9) What is a phospholipid? What is their main importance in biology? Explain how and why phospholipids form a bilayer in water (following the self-assembly rule). Phospholipids-similar to a fat molecule, but has only two fatty acids attached to glycerol instead of three. Phospholipids are essential for cells bc they are major constituents of cell membranes. Phospholipids are composed of a hydrophilic (water loving) phosphate head and 2 tails of hydrophobic (water hating) fatty acids. When grouped together, the fatty acid tails tend to line themselves up facing each other, away from the water (self-assembly). This makes sure that the phosphate heads ALWAYS face the surrounding water, as they are hydrophilic

General Biology 1

Ch 5 (Macro[bio]molecules) Study Guide Questions

II) Proteins & Nucleic Acids 1) What are the building blocks of proteins? How many kinds are there? Where are they similar and where do they differ from each other structurally? Amino Acids are the building blocks of proteins There are 20 types of amino acids All amino acids contain a Carboxyl group and an Amino group. It is the side groups (-R) that make each amino acid different from the others. 2) What is a peptide bond and how does it form? A peptide bond is a covalent bond formed when the carboxyl group of one amino acid molecule reacts with the amino group of the other amino acid molecule, causing the release of a molecule of water 3) What functions can proteins provide? Catalysts (enzymes) Immune systems (antibodies) Structure (connective tissue) Movement (muscle fiber contractions) Signaling (Insulin) Transport (membrane proteins) i.

Describe what an enzyme is by explaining its structure and how they work and why they’re so important to living things. They are catalysts that speed up chemical reactions, and carry-out chemical reactions. Enzymes are made up of chains of amino acids, and have a specific shape that allow chemicals to react with the enzyme. They are important to living things because they allow cells to reproduce and grow.

4) Explain what is meant by primary, secondary, tertiary and quaternary structure of a protein. 1. Primary: refers to the unique sequence of amino acids in the protein. All proteins have a special sequence of amino acids, this sequence is derived from the cell's DNA. 2. Secondary: the coiling or bending of the polypeptide into sheets is referred to the proteins secondary structure. alpha helix or a beta pleated sheet are the basic forms of this level. They can exist separately or jointly in a protein. 3. Tertiary: The folding back of a molecule upon itself and held together by disulfide bridges and hydrogen bonds. This adds to the proteins stability. 4. Quaternary: Complex structure formed by the interaction of 2 or more polypeptide chains.

General Biology 1

Ch 5 (Macro[bio]molecules) Study Guide Questions

i.

Make a simple sketch to help illustrate your explanation.

ii.

Why is the three-dimensional shape of a protein so important? Give an example. It is essential for function. If enzymes lose their shape (denatures)- it can no longer catalyze it reaction. An example is the white of an egg becoming opaque during cooking because the denatured proteins are insoluble and solidify.

5) Explain what denaturation of a protein is and give an example. Denaturation is when the protein loses its natural shape and cannot properly catalyze its reaction. An example is the white of an egg becoming opaque during cooking because the denatured proteins are insoluble and solidify 6) What are the three components of a nucleotide?

5-carbon sugar(pentose) Phosphate Nitrogenous Base 7) How are nucleotides linked together to form nucleic acid chains? To which end of the chain are new nucleotides added? Monomers of nucleotides linked together by -OH on 3' carbon and -PO4 on the 5' carbon of next

General Biology 1

Ch 5 (Macro[bio]molecules) Study Guide Questions

8) What is DNA? DNA- Deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the carrier of genetic information. i.

How do the purine bases differ from the pyrimidines? Which bases pair with each other, and what kind of bonds hold them together (including how many bonds in each pair)? The main difference is the number of carbon nitrogen ring bases, purines (A&G) have two while pyrimidines (T&G) only have one. T=A- forms two hydrogen bonds & C=G- forms three hydrogen bonds

ii.

Describe the three-dimensional shape of the DNA molecule and how its components are arranged (include the term “anti-parallel” in your discussion).

The three-dimensional structure of DNA is a double helix, The two backbones run in opposite directions from each other; this arrangement is referred to an antiparallel. It looks like a twisted ladder. 9) What is RNA? RNA-Ribonucleic acid, a nucleic acid present in all living cells. Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins 10) In what ways do DNA nucleotides differ from RNA nucleotides? RNA reads DNA and synthesizes protein RNA is a single helix instead of double RNA has a ribose sugar RNA has a different base for A, instead of T, its U. (uracil)...