HW 106 Q1-12,14,15

1) b
2) b
3) c
4) b
5) b
6) d
7) b
8) It consists of carbohydrates, that allows for energy to be stored.
9) Glucose, sucrose and starch are related because they are all carbohydrates and sugars.
10) Steroids are lipid molecules in which the carbon skeleton forms four fused rings. They circulate in one's body as chemical signals as well as acting as membranes that surround one's cells.
11) Polypeptide are related to proteins because they link amino acids together in a change and proteins consists of such polypeptide chains.
12) Denaturation affects the ability of a protein to function because it causes the protein to unravel and lose its natural shape because of an unfavorable change in the environment.

Summary 5.5

To start a chemical reaction, one needs to weaken the chemical bonds found in the reactants. This process requires that the molecules be able to absorb energy and it is known as activation energy. One way to weaken the chemical bonds is to heat it up, some cellular reactions use something known as catalysts, which speed up the chemical reaction. The main catalysts of chemical reactions are known as enzymes which are specialized proteins. An enzyme catalyzes only one type of reaction by specific reactions only allow enzyme of a certain shape and a specific reactant acted upon by an enzyme is called the enzyme's substrate. The substrate only fits into a certain region of an enzyme known as the active site.

Images:
http://waynesword.palomar.edu/images/enzyme5.gif
(Enzyme connecting to a substrate)
http://www.accessexcellence.org/RC/VL/GG/images/enzyme.gif
(Enzyme activity)

Concept Check
Explain the role of activation energy in a reaction. How does an enzyme affect activation energy?
Activation energy is the start-up energy for a reaction. An enzyme can affect activation energy by acting as a catalysts that speed up the chemical reactions.
Describe how a substrate interacts with an enzyme.
A substrate interacts with an enzyme by the enzyme acting upon a specific reactant, and the substrate then fits into a particular location of the enzyme known as the active site.

Summary 5.4

Protein is a polymer that is constructed from a set of just 20 different monomers known as amino acids. Each amino acid monomer consists of a central carbon atom attached to four other atoms or molecules through covalent bonds. Polypeptide is a chain that creates proteins by linking amino acids. These chains are at least 100 amino acids in length. A protein in the simple form of amino acids are connected together can not use its functions. Denaturation is a proccess in which an unfavorable change in the quality of the environment that causes a protein to unravel and lose its normal shape.

Images:
http://www.bio.mtu.edu/campbell/bl4820/lectures/lec1/protein1.gif
(Scientific representation of a kind of protein molecule)
http://plantandsoil.unl.edu/croptechnology2005/UserFiles/Image/siteImages/AminoAcidLG.gif
(Representation of a kind of amino acid)
http://web.siumed.edu/~bbartholomew/images/chapter5/F05-14.jpg
(Representation of denaturation of DNA, a kind of protein)

Concept Check:
Give at least two example of proteins you can "see" in the world around you. What are their functions?
Two examples of proteins that you can "see" in the world around you is hair and muscles. Hair keeps one warm and makes one have a better sense of touch. Muscles help you move and they keep you alive in the case of the heart muscle.
Relate amino acids, polypeptides, and proteins.
Amino acids is a central carbon atom attached to four partners through covalent bonds, polypeptides are consisted of amino acids and proteins are a polymers also made of amino acids.
Explain how heat can destroy a protein.
It can destroy a protein by unravelling and losing its normal shapes, because it breaks some forces that bond two molecules or atoms together.
Which parts of an amino acid's structure are the same in all amino acids? Which part is unique?
Amino acid's carbon partners and the hydrogen atoms are the same in all amino acids. However,f the "side group" that attaches to the fourth bond of the central carbon is unique.

Summary 5.3

Some liquids' inability to mix with water is similar to many other water-avoiding compounds to be called lipids. Molecules that avoid water is known as hydrophobic, a property that is evident in the boundary that surrounds and contains the aqueous contents of your cells. Fat consists of a three-carbon backbone attached to three fatty acids. Saturated fat is a fat in which all three fatty acid chains contain the maximum possible number of hydrogen atoms. Unsaturated fat contains less than the maximum numer of hydrogen atoms in in one or more of its fatty acid chains. Cholesterol is an essential molecule found in the membrame that is around your cells.

Images:
http://fig.cox.miami.edu/~cmallery/255/255chem/p2x2x3.jpg
(A brief overview and diagram of hydrophilic molecules.)

For more information:
http://en.wikipedia.org/wiki/Hydrophilic
(Information about the hydrophilic property)
http://www.dietobio.com/dossiers/en/fatty_acids/molecule.html
(A brief introduction to a Fat Molecule and its Components)

Content Check:
What property do lipids share?
Lipids are hydropholic that allows them to avoid water molecules.
What are the parts of a fat molecule?
A fat molecule consists of a three-carbon backbone called glycerol attached to three fatty acids.
Desribe two ways that steroids differ from fats.
Two ways that steroids differ from fats are that have different structures and functions.
What does the term unsaturated fat on a food label mean?
The term unsaturated fat on a food label mean that they might be healthy and can build up deposits of lipid known as plaques.