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Tuesday, September 9, 2008

Homework Questions 1-12, 14, 15

MULTIPLE CHOICE

1.)
b. sucrose
2.)
b. carbohydrate
3.)
c. hydrophilic
4.)
b. lipid.
5.)
b. side groups
6.)
d. substrate
7.)
b. cools a reaction, slowing it down

SHORT ANSWER


8.) Besides satisfying your hunger, why else might you consume a big bowl of pasta the night before a race?
You might also consume a big bowl of pasta the night before a race because
pasta is composed of carbohydrates which store the energy in your body for a long period of time, allowing more energy in the upcoming race.
9.) How are glucose, sucrose and starch related?
Glucose, sucrose and starch are related because they are allpolysaccharides which are a type of carbohydrates and they are all a type of sugar.
10.) What are steroids? Describe two functions they have in cells.
Steroids are lipid molecules in which the carbon skeleton forms four fused rings. Steroids are a hydrophobic substance that circulate your body as chemical signals as well as acting as membranes that surrounds different cells.
11.) How are polypeptides related to proteins?
Polypeptides are related to proteins because proteins are made up of one or more polypeptides chains which are linked together into amino acid chains.
12.) How does denaturation affect the ability of a protein to function?
Denaturation affects the ability of a protein to function because if a protein is located in an unfavorable environment, some including a variety of change in pH, temperature or other issues of heat, the protein may unravel and lose its normal shape. Some examples of denaturation include frying an egg as the egg white changed from a clear liquid to a white solid during cooking because heat denaturates the egg's proteins.
ANALYZING INFORMATION
14.) a The molecule represented by a question mark is a water molecule that has been removed during the chemical reaction of dehydration between two amino acids as they join together. Each time amino acids are added to a chain, a water molecule is removed.
b. This reaction is called a dehydration reaction because it involves removing (de) water (hydro). Each time a monomer is added to a chain, a water molecule is released. Same thing happends when a monomer is released, water is added to break it down.
c.If an amino acid were added to this chain, it can attach itself to the OH of the reaction or the H on the other end of the reaction.

15. ) a. Enzyme A performs the best at around 38 degrees Celsius and Enzyme B performs the best at 78 degrees Celsius.
b..Enzyme A is found in humans and enzyme B is a thermophilic enzyme.
c. If the rate of the reaction catalyzed by enzyme A slows down at temperatures about 40degrees Celsius, then the reaction will continue to slow down and become short.

Saturday, September 6, 2008

Concept Check 5.5 (:

ENZYMES ARE PROTEINS THAT SPEED UP SPECIFIC REACTIONS IN CELLS
-to start a chemical reaction, it if first necessary to weaken chemical bonds ion the reactants molecules
-
Activation Energy: minimum amount of energy required to trigger a chemical reaction and activate the reactants

-to provide activation energy: heat up the mixtures of molecules.
-hotter molecules collide with enough energy to weaken bonds, whereas cooler molecules collide with less energy
-heating cell can cause many unnecessary reactions to occur at once
Catalysts: compounds that speed up chemical reactions that cellular reactions depend on for assistance
Enzymes: main catalysts of chemical reactions in organisms that are specialized proteins
-enzymes provides a way for reactions to occur at cell's normal temperature.
-enzymes don't supply activation energy to reacting molecules, but lowers the energy required so the reaction can proceed at normal temperature
-enzyme catalyzes specific kinds of chemical reactions


HOW ENZYMES WORK
-enzymes fit in the shape of just one particular reactant molecule, therefore it only catalyze on type of reactions
-Substrate: specific reactant acted on by an enzyme.
-Active Sit: region of an enzyme into which a particular substrate fits.
-fit between substrate and enzyme is not rigid.
-as substrate enters active site, it changes its shape slightly, to fit better
-the tighter grip may also bend the substrate, weakening bonds
-sucrose is slightly distorted when entering the active site in a reaction
-weakened bond reacts with water
- the result is two products: a glucose molecule and fructose molecule.
-if either one of the results are released, the enzyme active site would accept another sucrose molecule.
-another way that an enzyme can lower activation energy is by accepting two reactant molecules into adjacent sites
-enzymes structure and shape are essential to its function.
-factors such as pH and temperature is greatly affects the enzymes work, or if it can work at all
-cells can only survive and function within certain ranges of conditions in temperature, etc.













CONCEPT CHECK:
1. Explain the role of activation energy in a reaction. How does an enzyme affect activation energy?
The role of the activation energy in a reaction is to start up the
required molecules to absorb energy which is to trigger a chemical reaction and activate the reactants, allowing a chemical reaction to occur. An enzyme affects activation energy because it speeds up cellular reactions and provides a way for reactions to occur at cell's normal temperature.

2. Describe how a substrate interacts with an enzyme.
A substrate
interacts with an enzyme by helping this specific reactant fit into a particular region, the active site. When it fits in the active site, the active site changed slightly, fitting the substrate better.

Wednesday, September 3, 2008

Concept Check 5.4 (:


THE FUNCTIONS OF PROTEINS
- A PROTEIN is a polymer constructed from a set of just 20 kinds of monomers called amino acids
-proteins are responsible to day to day functioning of organisms
-proteins form structures such as hair, fur and make up muscles and provide long term nutrients storage
-proteins work in bloods, defending harmful substances, conveys messages from one cell to another, controls chemical reactions.








AMINO ACIDS
-Each AMINO ACID monomer consists of a central carbon atom bonded into four partners
-Three partners are the same in all amino acids
-One partner is a hydrogen acid
- the side group differs in each amino acid
-side group is responsible for properties of each amino acid such as if its is hydroxyl









BUILDING A PROTEIN
- Cell create proteins by linking amino acids together into a chain called POPYPEPTIDE
-Each link is created by a dehyrdation reaction between amino group of one amino acid and the carboxyl group of the next amino acid
-can arrange amino acids in different orders to make proteins

PROTEIN SHAPE
- a functional protein consists of one or more polypeptides precisely twisted, folded and coiled into a unique shape
-a protein's shape is also influenced by surrounding environment, generally water
-an unfavorable change in temperature, pH or some other quality of the environment can cause a protein to unravel and lose its shape.
-called DENATURATION
-like frying an egg is denaturation

DENATURATION

Concept Check:

1. Give at least two examples of proteins you can see in the world around you. What are their functions?
Fish is a type of protein and it function as a nutrient. An egg is also a protein you can see in real life
2. Relate amino acids, polypeptides, and proteins.
They are all made up of amino acids as amino acids are the basis of polypeptides and proteins. The structure is with amino acids linking together at the bottom to make polypeptides. Proteins are created by the chain of polypeptides with protein as a final product.
3. Explain how heat can destroy a protein.
Heat can destroy a protein by causing it to unravel and lose its shape, like frying an egg.
4. Which parts of an amino acid's structure are the same in all amino acids? Which part is unique?
The same parts are the central carbon atom and the unique part is the side group is responsible for properties of each amino acid such as if its is hydroxyl.

Concept Check 5.3 (:

Characteristics of LIPIDS
-
LIPIDS are a typical class of water-avoiding compounds such as Oil
- Water avoiding molecules are said to be HYDROPHOBIC
-Lipids acts as a boundary that surrounds and contains watery contents of your cell
- Common Lipids are like fats which store energy in
your body


FATS
- FAT consists of three-carbon backbone ca
lled glycerol attached to three fatty acids, which contain long hydrocarbon chains
-Some fats are solid at room temperature while othe
rs fats, oils are liquid
- fatty cushion stores energy for later use and cushion your organs and provide your body with insulation
-SATURATED FAT: is a fat which all three fatty acid chains contain the maximum possible number of hydrogen atoms
-Saturated fat forms single bonds with others and hy
drogen atoms, and are solid in room temp, butter
-UNSATURATED FAT: contains less than the maximum number of hydrogen atoms on one or more of its fatty acid chains, because some of its carbon atoms are double-bonded to each other
-unsaturated fat include fruits, veggies

-too many saturated fat can be unhealthy causing blood flow problems

UNSATURATED FAT

SATURATED FAT


STEROIDS
-
A lipid molecule in which the carbon skeleton forms four fused rings is STEROID
- Steroids are hydrophobic
-Estrogen steroids a female sex hormone, and testosterone, male sex hormone circulation by sending chemical signals

- CHOLESTEROL: an essential molecule found in the membranes that surround your cells.
-cholesterol has a bad reputation of high levels in particular cholesterol contain substances, increasing risks of heart disease


Concept Check:

1. What property do lipids share?
Lipids are all sharing the same property of being hydrophobic, water-avoiding molecules.
2. What are the parts of a fat molecule?
The parts of a fat molecule are three=
-carbon backbone called glycerol attached to three fatty acids, which contain long hydrocarbon chains
3. Describe two ways that steroids differ from fats?
Steroid differ from fats in structure and function. Steroids circulate body signals, and their structure are different from those of lipids.
4. What does the term unsaturated fat on a food label mean?
Unsaturated
fat contains less than the maximum number of hydrogen atoms on one or more of its fatty acid chains, because some of its carbon atoms are double-bonded to each other. Some examples of unsaturated fat include fruits, veggies and fish.


Monday, September 1, 2008

Concept Check 5.2 (:

SUGAR / CARBOHYDRATE

- an organic compound made up of sugar molecules.

- contain the elements: carbon, hydrogen and oxygen

-ratio: 1carbon, 2hydrogen 1 oxygen

- these are a type of carbohydrates

-WHEAT

-BREAD














MONOSACCHARIDES:

- simple sugars containing just one sugar unit

-Examples: glucose, fructose, lactose

-many mono saccharides are found in sweet
things

-the right picture shows the complete molecular structure of glucose, sucrose and starch.

-glucose supply the fuel for cellular work



DISACCHARIDES:

- constructed with two monosacchrides, double sugar using the dehydration reaction


- Sucrose is the most common disaccaride


- Sucrose consists of a glucose molecule linked to a fructose molecule



-Sap of maple trees are sucrose



-Once consumed, sucrose can break down into glucose and fructose and used right away.





POLYSACCHARIDES:

-Long polymer chains made up on simple sugar monomers
-complex carbohybrates
- starch is a polysaccharides, consists of glucose monomers
-Starches include: potatoes, rice and corn


- glycogen is the excess sugar in the form of a polysaccharides
-

CELLUSE: serve as building materials

- almost all carbohydrates are hydrophillic

-however, celluse and starch and others don't dissolve in water



Concept Check:

1.Explain the difference between a monosaccharide and a disaccharide.Give an example of each. The difference between a monosaccharide and disaccharide is that a monosaccharide is a simple sugar with just one unit of sugar, while disaccharides are two monosaccharide together. A monosaccharide will be glucose and a dissaccharide will be sucrose, which is glucose and fructose added together.

2.Compare and contrast starch, glycogen, and cellulose. Starch, cellulose and glycogen are all made up of glucose monomers. Starch is a polysaccharides found in plants cells while glycogen is a excess sugary in form of polysaccharidesfound in animals such as turkeys. Cellulose on the other hand, serve as building materials to make fiber from plants.

3.How do animals store excess glucose molecules.Animals store excess glucose molecules in a form of glycogen since glycogen is the excess sugar found in animals.