Unit 2 Test Review – Chemistry of LifeName ______Hour _____

Macromolecule Structure and Function – LT 2.1

  1. What are the 6 most common elements in living organisms or organic molecules?

Nitrogen, Carbon, Hydrogen, Oxygen, Phosphorus, and Sulfur (NCHOPS).

  1. What are trace elements?

Elements necessary in small amounts for the body.

  1. Why is carbon so important to living things?

It can form 4 bonds; is versatile which allows it to form large molecules (macromolecules – the basis of life).

  1. The prefix mono means ____ONE____ in science, whereas the prefix poly means ___Many___.
  1. Complete the table below.

Macromolecule or Polymer / Monomer or Subunit / Functions in Human Body / Examples of foods that contain this molecule
Protein/Polypeptide / Amino Acids /
  • Building Body Structures (i.e. muscles)
  • Aids in digestion/Metabolism/Immunity
/ Meats, Beans
Carbohydrates or Polysaccharide / Mono-saccharides or Simple Sugars /
  • Short-term Energy Release
  • Fiber keeps us regular.
/ Fruits, Pasta, Breads
Lipids or Fats
(Saturated, Unsaturated, Trans) / (Triglycerides)
3 fatty acids & Glycerol /
  • Long-term Energy Storage
  • Insulation
  • Form Protective Coatings around cells and organs
/ Oils, Butter
Nucleic Acids
(DNA and RNA) / Nucleotides /
  • Forms Genetic information
/ Found in all living things and therefore all cells and food.
  1. What important information can be found on a food label in relationship to the things we have been studying this unit? Why is it important to have this information available for the public?

It can tell us the amount of carbohydrates, proteins, and lipids as well as some trace nutrients like sodium, etc. It can help us by knowing what is in your food, what the body needs overall, and helps us determine what is important to our overall health.

  1. As a mountain bike racer what do you think I might look for on a food label when choosing my diet plan for the week before a big race? Why?

Carbohydrates because this individual will need a great deal of short-term energy to complete the race.

A B C

Look at the Food Labels above and use them to answer the questions below.

  1. Food label A should be placed in which main food category/macromolecule group? Carbohydrate
  1. Why did you classify Food Label A in that group? Use Quantitative evidence to support your answer!

It has 40 grams of carbohydrates and much less fats (6 grams) and less protein (9 g).

  1. Food label B should be placed in which main food category/macromolecule group? __Protein______
  1. Why did you classify Food Label B in that group? Use Quantitative evidence to support your answer!

______It has the most protein (22g) and less carbohydrates (0g), and fats (10g)

  1. Food label C should be placed in which main food category/macromolecule group? ___lipids____
  1. Why did you classify Food Label C in that group? Use Quantitative evidence to support your answer!

____It has the most fats (23g), and les carbohydrates (1 g) and protein (14 g)________

  1. Which Food Label above would help you get the molecules necessary for long-term energy storage? Explain your answer.

_Food Label C because it has the most fat which is used for long term energy storage

  1. Which Food Label above would help you get the molecules necessary to prepare one week in advance for a long-distance swim, or perhaps, a triathlon? Explain your answer.

__Food Label A because it is made of a lot of carbohydrates which are good for “quick” energy

  1. A bodybuilder would choose Food Label Bover the other two choices to help build muscle

Digestion and Digestive System

  1. What is the difference between chemical and mechanical digestion?

Chemical digestion used chemicals like acids and enzymes to help break down food, where mechanical uses physical movement like chewing or stomach contractions to digest food.

  1. An example of chemical digestion would be…..

The enzyme amylase which is in our saliva to break down starch into simple sugars or monosaccharides.

  1. An example of mechanical digestion would be…..

Chewing your food or the muscular churning of food in the stomach

  1. Give 2 examples of an organ of the digestive system carry out both chemical & mechanical digestion?

Mouth and stomach do both types of digestion

  1. Where in the body do starches first start to break down? mouth
  1. What enzyme helps breaks down sugars and starches first? amylase
  1. In which digestive organ does the majority of nutrient absorption take place? Small intestine
  1. In which digestive organ does the majority of water absorption take place? Large intestine
  1. The liver produces bile which helps with the breakdown of fats
  1. What two types of compounds are found in the stomach to help it accomplish chemical digestion?

Acids and Enzymes

  1. Label the diagram to the right.

Which organ stores bile?

Gall Bladder

Acids, Bases, and pH

  1. Draw the pH scale below. Label it with numbers 1, 7, and 14. Also includethe titles: acidic, basic and neutral. You may use brackets to show the ranges.

1 7 14

______

neutral

  1. Place an X on the pH scale in the area there would be a strong acid, and place a star on the pH scale in the area where a strong base would be found.
  1. Something having a pH of 7.3 would be classified as a(n)Weak Base.
  1. Something having a pH of 5.0 would be classified as a(n) Weak Acid
  1. What are some examples of acidic foods or drinks?

Vinegar, soda pop, citrus fruits

  1. What are some examples of basic foods or drinks?

Broccoli, walnuts

  1. An example of a substance with neutral pH would be water.
  1. How is blood pH related to human homeostasis?

It is maintained between 7.35-7.45 (maintains a stable internal environment)

  1. How is pH related to environmental issues?

Acid rain can damage statues, monuments, forests, animals, aquatic life (i.e. dead lakes)

  1. How can pH affect the animals around the world?

If a fish is exposed to an environment with conditions that are too basic or acidic it can become sick and/or lead to death.

The pH of soil can be affected which can affect plant growth which ultimately limits the food source for various animals that are dependent on those plants.

  1. What affect can pH have on plants?
  • The pH of soil is important and can affect plant growth by decomposing organic matter and bacteria in the ground.
  • Some flowers change color based on pH

Enzyme Structure, Function, and Reaction Types

  1. A metabolic reaction that builds up larger molecules from linking smaller molecules together while creating water would be called dehydration synthesis (condensation)
  1. A metabolic reaction where a larger molecule is broken down into smaller molecules by an enzyme or acid while using water would be called hydrolysis
  1. Which class of proteins is responsible for speeding up chemical reactions that would otherwise be to slow to occur on their own? Enzymes
  1. What is the general function of enzymes?

To speed up a chemical reaction such as speeding up digestion and metabolism by building molecules or breaking them apart.

  1. Draw a simple condensation or dehydration synthesis reaction below.
  1. Draw a simple hydrolysis reaction below.
  1. When the body takes in extra sugars it chains them together for storage and later use, what type of reaction is this? Condensation (dehydration synthesis)
  1. A bear before it hibernates will need lots of reserve fat. What reaction type would be occurring in high amounts prior to them going to sleep? Condensation (dehydration synthesis)
  1. A person losing weight would be focused on causing which reaction type? hydrolysis
  1. Are enzyme’s recyclable? YES!
  1. What would be the monomer of an enzyme? An amino acid
  1. Draw an enzyme, substrate and active site and label the parts.
  1. Explain the relationship between an enzyme and its substrate. What analogy did we mention in class that helped us understand this relationship?

It is like a “lock and key” Each enzyme has a very specific substrate therefore the shapes have to match perfectly.

  1. What is denaturation? What happens to the enzyme’s active site?

Denaturation is when enzymes are damaged and its active site changes shape therefore the substrate can no longer fit in to that specific shape and the protein can longer function properly.

  1. What things could cause an enzyme to become denatured?

Heat, acids and bases

  1. What do you think would happen to you if the enzyme that controlled skin cell growth became denatured?

If the enzyme never turned on growth in the first place, you would never replace skin and could not repair damage. If the enzyme that controlled shutting off skin growth were denatured, then the skin cells could keep growing and cause a tumor.