Monday 10 November 2008

Summary

8.1

♥all green parts of the plant we can see contain cells with chloroplast which carries out photosynthesis.
♥both carbon dioxide and oxygen leave through the leaf by its stomato.
♥chloroplast's structure is very important for its function like mitochondria
♥inner membrane of chloroplast encloses stoma and thylakoids are suspended there
♥various structure of chloroplast helps to carry out photosynthesis
♥electrons from water are boosted "uphill" by the energy from sunlight so the chloroplast uses these "excited" electrons, along with carbon dioxide and hydrogen ions, to produce sugar molecules.
♥NADPH is an electron carrier very similar to the NADH
♥results of light reaction are ATP and NADPH
♥Calvin cycle does not use light directly but it requires two inputs supplied by light reaction, ATP and NADPH

8.2

♥visible light is wavelengths that our eyes can detect as a lot of colours
♥wavelengths that are shorter than visible light can damage organic molecules such as proteins or nucleic acids which can explain ultraviolet radiation can cause skin cance to us
♥when light shines on material which contains pigments can happen in three ways: absorbed, transmitted, or reflected
♥chloroplast pigments do not absorb green light well but the light passes through the leaf or reflects back
♥chlorophyll a absorbs blue-violet and red light and reflects green light
♥chlorophyll b absorbs blue and orange but reflects yellow-green
♥cluster of pigment molecules are the light gatherers
♥when pigment molecule absorbs light, one pigment's electron gains energy
♥when excited electron transfers energy, it drops back to ground state and the electron that recieved enery becomes excited
♥photosystem can be thought of as the "water-splitting photosystem" because the electrons are replaced by splitting a molecule of water. This process releases oxygen as a waste product, and also releases hydrogen ions.
♥electron transport chain connecting the two photosystems releases energy, which the chloroplast uses to make ATP of producing ATP is similar to cellular respiration
♥ light reactions convert light energy to the chemical energy of ATP and NADPH
♥photosynthesis also produces sugar
♥Calvin cycle uses the ATP and NADPH produced by the light reactions.

8.3

♥Calvin cycle reuses its materials each time the process occurs
♥Calvin cycle's inputs are carbon dioxide from air and ATP and NADPH from light reactions
♥Calvin cycle's output is an energy rich sugar molecule
♥sugar yet not glucose but smaller sugar name is G3P
♥The plant cell usese G3P as a raw material for making glucose and other organic molecules needs.
♥equation for photosynthesis is 6CO2+6H2O->->-> C6H12O6+6O2
♥light reactions take place in the thylakoid membranes
♥light reaction uses water as a reactant and produce oxygen
♥Calvin cycle takes place in stroma, it uses ATP and NADPH to change carbon dioxide to sugar
♥First step of photosynthesis is the flow of energy through an ecosystem, whree chmical energy passes from producers to consumers

Sunday 9 November 2008

Vocabulary & Concept Checks

8.1

chloroplast: The cellular organelle where photosynthesis takes place
chlorophylls: chemical compounds that give these organelles a green color
stroma: The inner membrane encloses a thick fluid
thylakoids: many disk shaped sacs suspended in the stroma
light reations: convert the energy in sunlight to chemical energy
Calvin cycle: makes sugar from the atoms in carbon dioxide plus the hydrogen ions and the high-energy electrons carried by NADPH




Concept Check



1.






2.The reactants for photosynthesis are carbon diocide and water and products are glucose and oxygen.
3.The two main stages of photosynthesis are light reactions and the Calvin cycle. Both of them uses hydrogen ions and they work in the chloroplast.


8.2

wavelength: the distance between two adjacent waves
electromagnetic spectrum: The range of types of electromagnetic energy, from the very short wavelengths of gamma rays to the very long wavelengths of radio waves,
pigment: a substance's color is due to chemical compounds
paper chromatography: Using a laboratory technique
photosystem: Within the thylakoid membrane, chlorophyll and other molecules are arranged in clusters

Concept Check
1. A leaf appears green because the material contains pigments which shines when light is given and that is chlorophylls.
2. When chlorophyll a absorbs light, it mainly absorvs blue violet and red light and reflects green light this is like the major role in the light reactions of photosyntheses.
3. The two molecules that are produced by the light reactions besides oxygen are hydrogen ions and NADPH.
4. The light reactions take place in the Thylakoid membrane in the chloroplast.

8.3

Concept Check
1.The inputs are carbon dioxide, ATP, and NADPH and output is energy-rich sugar molecule.
2.Light reaction uses each reactant from the overall photosynthesis equation. Calvin Cycle generates each product from the overall photosynthesis equation.
3.It is called a cycle because like Krebs cycle in cellular respiration, the starting material is regenerated each time the process occurs.
4. G3P is the direct product of photosynthesis. The plant take it in and make glucose or uses it for other organic molecules.
8.4

carbon cycle: the process by which carbon moves from inorganic to organic compounds and back
greenhouse effect: keeps the world climate warm enough for living things

Tuesday 9 September 2008

Chapter 5 Review pg.106-107 #1-12,14,15

1) c. water
2) d. glycogen
3) c. hyphilic
4) b. lipid
5) b. side groups
6) d. substrate
7) b. lowers the activation energy of a reaction
8)
9) They all consists of sugar.
10) Steroids are a lipid molecule in which the carvon skeleton forms four fused rings. It circulates in your body as chemical signals and cause some differences in appearance between men and women.
11) Polypeptide is a chain that creates protein by linking amino acids toghter.
12) It heats up unfolded proteins since the most of the forces that maintain folding are weak attractions between pairs of side groups, and between side groups and water.
14) a.
b. dehydration reaction
c. OH
15) a. 38 degrees for enzyme A and 78 degrees for enzyme B.
b. Enzyme A from bacteria and enzyme B for humans.
c.

Thursday 4 September 2008

Summary 5.5

-activation energy is a starting energy

-enzymes are the main catalysts of chemical reactions.

-catalysts speed up chemical reactions.

-enzymes does not supply activation energy but instead, it lowers the energy requirement barrier that reaction is resulted in normal cell temperature.

-a specific reactant acted upon by an enzyme is enzyme's substrate.

-sustrate fits into a region called active site.

-fit between sustrate and enzyme is not rigid.

-way that an enzyme can lower activation energy is by accepting tow reatant molecules in do adjacent sites.

-like proteins, enzyme's shape is senstive to changes in its environment.



Concept Check 5.5
1.Explan the role of activation energy in a reaction. How does an enzyme affect activation energy?
Activation energy is a start up energy tat activates reactant. It is the main catalyst of te reaction.
2.Describe how a substrate interacts with an enzyme.
If it fits into a region of the enzymes called active site. the region changes shape for it to fit.



Wednesday 3 September 2008

Summary 5.4

-protein is a polymer constructed from a set of 20 kinds of amino acids.

-proteins circulate in the blood and defend the body from harmful microorganisms and other act as signal, sending messages from one cell to another.

-each amino acid, a cetral carbon atom bonded to four partners, three central carbon's partners are same in all amino acids and one is hydrogen atom

-the difference for each amino type is the side group

-side group of amino acid are leucine, a hydrocarbon, attracts water.

-polypeptide is making amino acids into a chain

-a protein's shape is influenced by the environment, aqueous.

-process called denaturation is used when protein is heated.



Concept Check 5.4



1.Give at least two examples of proteins you can "see" in the world around you. What are their functions?

Hair and muscles. Hair makes animas to keep in temperature and their muscles make them strong.

2.Relate amino acids, polypeptides, and proteins.

Protein is polymer made from 20 kinds of monomers which is amino acids. Amino acid pairs the central carbon atom with four partners and linking them into a chain is polypeptide.

3.Expain how heat can destroy a protein.

The heat uses a process called denaturation which means heat denatures protein and makes it into a solid.

4. Which parts of an amino acid's structure are the same in all amino acids? Which part is unique?

They are all responsible for particular chemical properties of each amino acids and each type of amino acid is attached to the fouth bond of the central carbon.

Summary 5.3

-lipid molecules circulate in your body as chemical signals to cells


-lipids are fats stored in body


-some fats are solid in room temperature.


-carbon atoms in the fatty acid chains form single bonds with each other and rest bond with hydrogen atoms


-the fats in fruits, vegetables, and fish are unsaturated fat.


-saturated fats are unhealthy so it can cause heart disease.


-four focused rings in which the carbon skeletons forms is steroid.


-steroids are lipids because they are hydrophobic but different from fats structure and fuction.


-cholesterol is the best known steroid in.


-high cholesterol increases risk for cardiovascular disease.


Concept Check 5.3

1.What property do lipids share?

Water avoiding property like oil's.

2.What are the parts of a fat molecule?

The parts of a fat molecule are saturated fat and unsaturated fat.

3.Describe two ways that steroids dffer from fats.

Fats consist of a three-carbon backbone attached to three fatty acids. The carbon skeleton which forms four focused rings is steroids.

4.What does the term unstaturated fat on a food label mean?

Having less than the maximum number of hydrogen atoms.

Tuesday 2 September 2008

Summary 5.2

-sugars contain the elements carbon, hydrogen and oxygen, ratio of 1:2:1
-at the core of most sugar molecules found in nature are carbon skeletons that have a ring shape
-carbohydrate is an organic compound made up of sugar molecules
-simple sugars contain one sugar unit, monosaccharides eg) glucose, frutose and glactose.
-glucose exist in both straight chain and ring shaped forms

-sugar molecules, glucose are main supply for cellular work.

-cells break down glucose molecules and extract their stored energy (mostly not used immediately incorporated into larger carbogydrate)

-disaccharide, cell constructed by two monosaccharide.

-sucrose can be broken down into glucose and frucose and used right away. Body can store these after use.

-sucrose consist of a glucose molecule linked to fuctose molecule.

-when plants break down starch molecules, the stored glucose becomes available.

-humans and animals use plant starch for digestive system

-glycogen mostly stored in liver and muscle cells

-when body needs energy it breaks down glycogen and release glucose.

-cellulose and some of starch are not soluble.

Concept Check 5.2

1.Explain the difference between a monosaccharide and a disaccharide. Give an example of each.

Monosaccharide is one sugar unit and disaccharide is two sugar unit. Glucose, fractrose, and glactose are example of monossacharide and sucrose is an example of disaccharide.

2.Compare and contrast starch, glycogen, and cellulose.

Starch is a polysaccharide found in plant cell, glycogen is polysaccharide found in animals and cellulose is aso polysaccharides in plant that serves building materials.

3.How do animals store excess glucose molecules?

Animals store excess glucose molecules in a form of polysaccharide.