Chapter 5 Study Guide

Explain how monomers are related to their associated polymers

Monomers are small/basic molecules that chemically bond together to act as the building blocks for larger, complex structures called polymers 

Define a monomer 

Mono = one, Smallest form of the organic molecule 

Define a polymer 

Poly = many, A larger molecule made up of monomers 

Carbohydrates (monomers and polymers)

monosaccharide, starch  

Lipids (monomers and polymers)

fatty acid, fat molecule 

Proteins (monomers and polymers)

amino acid, polypeptide  

Nucleic Acids (monomers and polymers)

nucleotide, dna strand  

Explain the meaning of the phrase dehydration synthesis. 

Dehydration= removing water, synthesis= to bring together 

Describe the process of dehydration synthesis

These reactions create ploymers from monomers w/water as a by product 

Explain the meaning of the word hydrolysis

hydro= water, lysis= to break apart  

Describe the process of hydrolysis

A water molecule is added to the bond between two monomers. The water splits, and its parts attach to the separate molecules, breaking the bond. Repeating this process breaks a polymer down into its individual monomers 

Briefly explain how enzymes are used in metabolic reactions

Enzymes are proteins that speed up metabolic reactions in cells by lowering the amount of energy needed for the reaction to occur. They help reactions happen faster and more efficiently without being used up 

Carbohydrates (diseases)

Diabetes occurs when the body has trouble regulating blood glucose

Lipids (diseases)

Atherosclerosis can occur when fatty substances build up in artery walls

Proteins (diseases)

Sickle cell disease is caused by an abnormal form of hemoglobin, a protein

Nucleic acids (diseases)

Genetic disorders such as cystic fibrosis can result from changes (mutations) in DNA 

what monosaccharides has 3 carbons

triose

what monosaccharides has 4 carbons

tetrose

what monosaccharides has 5 carbons

pentose (example: ribose)

what monosaccharides has 6 carbons

hexose (example: glucose, fructose)

what monosaccharides has 7 carbons

heptose 

Aldose

The carbon-oxygen double bond is at the end of the carbon chain. Example: glucose

Ketose

The carbon-oxygen double bond is within the carbon chain (usually on the second carbon). Example: fructose

Storage polysaccharide

have coiled or branched shapes, which make them easier to store and break down for energy. Examples: Starch (plants) and glycogen (animals)

Structural polysaccharides

have long, straight chains that can form strong fibers for support. Examples: Cellulose (plant cell walls) and chitin (insect exoskeletons) 

how are Fats (triglycerides) structured?

Made of 1 glycerol molecule attached to 3 fatty acids

how are Phospholipids structured?

Made of 1 glycerol, 2 fatty acids, and a phosphate group. They have a water-loving head and water-fearing tails

how are Cholesterol structured?

Made of 4 connected carbon rings with a small hydrocarbon tail and an –OH group

how are Steroids structured?

Have a structure of 4 fused carbon rings. Cholesterol is an example of a steroid 

what is the function of Fats (triglycerides)

Store long-term energy, provide insulation, and cushion organs

what is the function of Phospholipids

Form the main structure of cell membranes

what is the function of Cholesterol

Helps maintain cell membrane stability and is used to make some hormones and other molecules

what is the structure of saturated fatty acids

Have no carbon-carbon double bonds, so the carbon chain is straight, so they pack tightly together and are usually solid at room temperature

what is the structure of unsaturated fatty acids? 

Have one or more carbon-carbon double bonds, which create bends or “kinks” in the chain, so they cannot pack as tightly and are usually liquid at room temperature

How are cis fatty acids structured?

The hydrogen atoms around the double bond are on the same side, causing the fatty acid chain to bend or kink preventing them from packing tightly together, so they are usually liquid at room temperature

How are trans fatty acids structured?

The hydrogen atoms are on opposite sides of the double bond, making the chain straighter, so they are usually more solid at room temperature 

What does the term amphipathic mean? 

a molecule has both a water-loving (hydrophilic) part and a water-fearing (hydrophobic) part

How does the structure of amphipathic molecules affect their chemical properties? 

Because amphipathic molecules have a water-loving part and a water-fearing part, they interact with water differently. This causes phospholipids to naturally arrange themselves into cell membranes, with the heads facing the water and the tails facing inward

What is the function of phospholipids? 

to form the cell membrane. They create a barrier around cells and help control what enters and leaves the cell 

Triglycerides (structure)

glycerol + 3 fatty acids  

Phospholipids (structure)

glycerol + 2 fatty acids + phosphate group  

Cholesterol/steroid (structure)

four fused carbon rings 

What are the functions of cholesterol in cells? 

Helps maintain the stability and flexibility of cell membranes, Helps make steroid hormones, Is used to make vitamin D and bile acids, which help with digestion 

What are the functions of steroids in cells? 

Act as hormones that send signals and regulate body processes, Help regulate growth, development, and reproduction, Some steroids help control metabolism and immune responses 

What are examples of steroids? 

Cholesterol, Estrogen, Testosterone, Cortisol, Aldosterone 

Know that peptide bonds are in proteins

the bond that connects amino acids together to make proteins. Amino acids are linked by peptide bonds to form polypeptide chains, which then fold into functional proteins 

What are the four levels of protein structure? 

Primary structure, Secondary structure, Tertiary structure, Quaternary structure 

What unique features make up the different levels of Primary structure

the specific sequence of amino acids in the protein

What unique features make up the different levels of Secondary structure

local folds such as alpha helices and beta sheets

What unique features make up the different levels of Tertiary structure

the overall 3D shape of one polypeptide chain.  

What unique features make up the different levels of Quaternary structure

how multiple polypeptide chains fit together to form one functional protein 

Describe how the chemical properties of each amino acids R-group directly 

affect protein shape

The chemical properties of the R-groups determine how amino acids interact with each other and their surroundings, causing the protein to fold into a specific shape

Draw the basic structure of an amino acid

H 

       | 

H₂N — C — COOH 

       | 

       R 

What are the four categories of amino acid R-groups? 

Nonpolar, polar, acidic, basic 

Nonpolar (chemical properties)

hydrophobic; avoid water

Polar (chemical properties)

hydrophilic; interact with water

Acidic (chemical properties)

negatively charged

Basic (chemical properties)

positively charged

How does primary structure influence secondary structure? 

the amino acid sequence affects where the protein can form hydrogen bonds, which create structures like alpha helices and beta sheets 

How does secondary structure influence tertiary structure? 

determining how the alpha helices and beta sheets fold and interact with each other to create the protein’s overall 3D shape 

How does tertiary structure influence quaternary structure? 

allowing individual polypeptide chains to interact and fit together to form a functional protein 

What kinds of jobs do Enzymes do in cells and organisms?

speed up chemical reactions

What kinds of jobs does Transport do in cells and organisms?

move substances around cells or through the body

What kinds of jobs does Structure do in cells and organisms?

provide support and strength, like collagen

What kinds of jobs does Defense do in cells and organisms?

help protect the body, such as antibodies

What kinds of jobs does Communication do in cells and organisms?

act as hormones or receptors to send and receive signals

What kinds of jobs does Movement do in cells and organisms?

help cells and muscles move

What kinds of jobs does storage do in cells and organisms?

store important substances, such as iron 

Describe collagen’s structure

Has a long, strong, triple-helix structure that forms fibers

Describe Hemoglobin’s structure

Has a globular (rounded) structure made of four polypeptide chains. It has regions that bind oxygen

Explain the function of collagen

Provides strength, structure, and support to tissues such as skin, bones, tendons, and cartilage

Explain the function of hemoglobulin

Carries oxygen from the lungs to the rest of the body and helps transport some carbon dioxide back to the lungs 

Briefly explain how a change in a proteins structure can affect the function

A change in a protein’s structure can change its shape, which can prevent it from working properly. Since a protein’s function depends on its shape, even a small change can affect its function 

What is denaturation? 

when a protein loses its normal shape because of factors like heat, extreme pH, or chemicals

What is the result of denaturation? 

a protein loses its normal shape and usually its function. It may no longer work properly

Explain how X-ray crystallography is used to study the shape of various molecules

by shining X-rays through a crystallized sample. The X-rays create a diffraction pattern, which scientists use to figure out the molecule’s structure and shape 

DNA

Usually double-stranded, contains deoxyribose sugar, and uses the bases A, T, C, G

RNA

Usually single-stranded, contains ribose sugar, and uses A, U, C, G (uracil replaces thymine)

How does the structures of DNA affect it’s functions in the cell? 

double-stranded and more stable, making it good for long-term storage of genetic information

How does the structures of RNA affect it’s functions in the cell? 

usually single-stranded and more flexible, allowing it to carry genetic instructions and help make proteins

Sugar (Nucleotides)

the 5-carbon sugar in the middle

Phosphate (Nucleotides)

the phosphate group attached to the sugar  

Nitrogenous bas (Nucleotides)

the base attached to the sugar 

Draw the basic structure of a nucleotide

Phosphate group 

             | 

             ↓ 

        [ PHOSPHATE ] 

             | 

             | 

        [   SUGAR   ] 

             | 

             | 

        [ NITROGENOUS 

           BASE ] 

What is different about the structure of a pyrimidine

have one 6-membered ring

What is different about the structure of a purine

have two fused rings (one 6-membered and one 5-membered)

Which nucleotides are pyrimidines

Cytosine (C), Thymine (T), Uracil (U)  

Which nucleotides are purines? 

Adenine (A), Guanine (G)

Explain how genomics and proteomics are providing information essential in fighting disease

Genomics studies an organism’s DNA and genes, while proteomics studies its proteins. They help scientists understand genetic causes of diseases, identify disease-related changes, develop targeted treatments, and predict how a person may respond to certain treatments