Summary 7.2

• energy is ability to perform work
• energy- moved against an opposing force
• two basic forms are kinetic, potential energy
• anything moving, has kinetic energy
• cannot destroy or create energy, cna be converted
• potential energy, energy stored because of position or arrangement of object
• random molecular motion - thermal energy
• energy provided by food
• potential energy depends on arrangement of atoms
• organic molecule cell structure - rich in chemical energy
• rearrangement of atomes releases potential energy
• organic molecules in food = high in chemical energy
• complex molecules broken down into simpler ones
• cars only use up 25% of the energy from gasoline
• glucose + oxygen react = cellular respiration
• 40% into energy, 60% into heat
• retaining some heat that is lost, keeps constant temperature
• sitting in class, radiates heat as 100 watt lightbulb
• calorie = amount of energy required to raise the temp of 1 gram of water by 1 degrees
• food expressed in kilocalories

Concept Check

1. At the top of the staircase, you have potential energy. It is stored as you prepare to walk down the stairs. As you slowly walk down the staircase, the potential energy is converted into kinetic energy.

2. During exercise, your body breaks down complex molecules into simpler molecules. 40% is used to power your body while you exercise. The other 60% however, is lost through sweat and other cooling methods.

3. 10kcal of energy = 10,000 calories. 100g water = 100(1) gram of water. 10kcal would raise 10 degrees of 100g of water

Summary 7.1

• classify organism, how they get food
• self feeders - autrotrophs
• photosynthesis - using the sun's energy to make sugar
• producers - make food themselves
• heterotrophs - consumers
• producers/consumers obtain energy from food through cellular respiration
• ATP (adenosine triphosphate) the result of cellular respiration
• photosynthesis and cellular respiration recycle water, CO2, oygen, C6O12H6
• plants and animals both use oxygen for the process
• contiously recycle the materials

Concept Check

1. Autotrophs are organisms that can make their own food. Autotrophs include plants that do not need to consume other things to get their food. Heterotrophs on the other hand, are organisms that aren't able to make their own food like autotrophs. Heterotrophs such as animals and humans have to consume autotrophs or other heterotrophs to get food.

2. Glucose is where plants get their energy from. They use a process called photosynthesis to use sunlight to convert water and CO2 into glucose so they can get the energy that they need.

3. The sun is the main source of energy for photosynthesis that takes place in plants. The plants take in the sun to convert H2O and CO2 into sugar. The heterotrophs eat these plants to take in energy for themselves, which means, that if plants cannot survive, animals would also die out.

Chapter 5 Review Questions

pg 106 1~4, 12, 14,15

1) Which of the following is NOT an organic molecule?
c. water

2) Which of the following terms includes all the other terms on this list?
b. carbohydrates

3) Which term is most appropriate to describe a molecule that dissolves easily in water?
c. hydrophilic

4) Cholesterol is an example of what kind of molecule?
b. lipid

5) The 20 amino acids vary only in their
b. side groups

6) A specific reactant an enzyme acts upon is called the
d. substrate

7) An enzyme does which of the following?
b. lowers the activation energy of a reactant

8) Besides satisfying your hunger, why else might you consume a big bowl of pasta the night before a race?
When you need to run for a race, you need extra energy, and extra energy needs extra sugar to be stored in your body. So, the night before the race, it would be reasonable to devoure a big bowl of pasta for the excess sugar you need the next day.

9) How are glucose, sucrose, and starch related?
Glucose, sucrose, and starch are all sugars. Also, glucose is a part of sucrose and also, 4 glucose molecules make up starch.

10) What are steroids? Describe two functions they have in cells.
Steroids is a kind of lipid that acts as a signal trasmitter. It travels around the cell to send messages. Estrogene and testosterone in the body give male and female characteristics to people and also, a well know steroid, cholesterol, is in the membrane that surrounds your cells.

11) How are polypeptides related to proteins?
Long polypeptide chains, made up from many variations of amino acids, make a specific shape of the protein that helps determine it's functions.

12) How does denaturation affect the ability of a protein to function?
When denaturation happens, due to the change in pH or temperature, hot molecules can collide with the uncoiled polypeptides and breaks the protein apart, thus making it loose it's ability to function properly.

14) Analyzing Diagrams. The reaction below shows two amino acids joining together.
a. One product of this reaction is represented by a question mark. What molecule is it?
It is a water molecule
b. What is this kind of reaction called? Explain.
It is called a dehydration reaction because when the two amino acids connect, the water molecule is released.
c. If an amino acid were added to this chain, at what two places could it attach?
The two molecules can attach to the hydrogen molecule on the left, and the OH molecule on the right side.

15) Use the graph to answer the questions below.
a. At which temperature does enzyme A perform best? Enzyme B?
Enzyme A performs best at around 38 degrees while enzyme B performs best at around 78 degrees.
b. Knowing that one of these enzymes is found in humans and the other in thermophilic (heat-loving) bacteria, hypothesize which enzyme came from which organism.
Enzyme A is most likely the enzyme that is in humans because the human has a body temperature close to around 38 degrees (36 to be exact) and the heat loving bacteria probably contain enzyme B.
c. Propose a hypothesis that explains why the rate of the reaction catalyzed by enzyme A slows down at temperatures above 40°C.
After 40 degrees celcius, the reaction could carry on without any more help of catalyst A. That would mean that the temperature was hot enough for the enzymes to continue on with the reaction.

Summary; section 5.5

Summary

• weaken chemical bonds for chemical reaction
• to do this, molecules need to absorb energy
• ex) add heat, weaken bonds
• heating = unnecessary reactions
• rely on catalysts
• catalyst = compounds speeding chemical reactions
• enzymes = example of catalyst
• enzymes - reaction at cell's normal temp
• lowers energy required for chemical reactions
• enzyme catalyze different reactions
• enzyme fits shape of specific reactant molecules
• specific reactant acted upon by enzyme = substrate
• substrate fit into the active site
• shapes change to fit substrate
• enzyme lower activation energy = "accepting two reactant molecules" (pg104)
• accepting into "adjacent sites"(pg104)
• holding reactant - react more easily
• enzyme also sensitive to heat or ph change

Concept Check
1. Activation energy is the amount of energy that is needed so that a chemical reaction can begin and take affect. The enyzme however, lowers the activation energy so that cells can react at normal or regular temperature
2. The substrate is fitted into the active site, or particular sites on the enzyme and the substrate lets the enzyme do it's job. By doing this, the enzyme lowers the activation energy for the chemical reaction.

Summary; section 5.4

Summary

• 20 kinds of monomers, or amino acids make up the polymer protein.
• proteins responsible for day to day functions
• ex)long term nutrient storage, muscles
• signals -send to other cells in body
• amino acids - carbon atom + 4 partners
• 3 of the partners are always the same
• hydrogen, carboxyl group, amino group
• the alternating one/fourth group/side group is different
• side group sometimes = R group
• amino acids link together to create proteins
• these chains are called a polypeptide
• dehydration provides a link for the amino acids
• proteins = one or more polypeptides
• arranging amino acids in different ways produce different proteins
• polypeptides are usually 100 amino acids
• a LOT of variations avaliable
• proteins are like a yarn ball
• temperatures, and changes in pH can unravel the protein
• denaturation is when a protein looses it's shape
• heating can unravel a protein
• if a protein looses's it's shape, then looses it's functions

Concept Check
1. Hair and muscles are proteins that you can see. Hair protects your head, and muscles are parts of the body that enables you to move and create things such as facial expressions
2. Hundreds of amino acids connect to make a polypeptide. Then, one or more polypeptides twist and thus make a protein.
3. When heat is added to a protein, the weak bonds cannot stand the hot molecules that come colliding into them. So, what happends is that the weak bonds start to break and then, at the end, the protein unravels.
4. The hydrogen, the amino group and the hydroxyl group are the consistant or similar part of an amino acid. The 4th partner is the special one, and the fourth partner decides what kind of special protein it will be. The fourth partner differenciate one protein from another one.

Summary; section 5.3

Summary:

• oil is water avoiding or hydrophobic or "water fearing"
• water avoiding compounds are called lipids
• lipids contain the water/aqueous solution in cells
• some others, circulate in the body as signals
• fats are lipids that have a glycerol that is attached to three fatty acids, all the fatty acids are connected to long hydrocarbon chains.
• some fats are liquid/some are solid
• fat cushions organs
• body insulation
• saturated fats/unsaturated fats
• saturated = all single bonds, maximum hydrogens
• unsaturated = a double bond somewhere in between
• saturated - solid, unhealthy
• unsaturated - liquids, healthier
• lipid buildup, reduce blood flow, heart disease
• carbon skeleton w/ 4 fused rings = steroid
• core set = 4 rings, differ in locations + functional group
• hydrophobic so it's a lipid
• signals - estrogen, testosterone
• Cholestrol molecule in membranes of cell
• high levels = bad for body
• increase - cardiovascular disease

Concept Check:
1. All lipids are hydrophobic or "water fearing".
2. There is the glycerol backbone, and these backbones are connected to 3 fatty acids.
3. steroids are four carbon skeletons that are fused together in a ring. Also, the signals that these steroids send, are different from the fats.
4. If a food has the label "unsaturated", it means that it is probably plant oil, and that it has a double bond somewhere in the 3 fatty acids.