8.2 The Light reactions convert light energy to chemical energy

=8.2 The light reactions convert light energy to chemical energy=

*Vocab

-wavelength=>distance between adjacent waves

-electromagnetic spectrum=> range of types of electromagnetic energy from gamma waves to radio waves

-pigment=>chemical compound that determines a substance's color

-paper chromatography=> laboratory technique used to observe the different pigments in a material

-photosystem=>cluster of chlorophyll and other molecules in a thylakoid

*Light Energy and Pigments

-Sunlight: form of electromagnetic energy

gamma rays-X-rays-UV-visible light-infrared-microwaves-radiowaves

>Pigments and Color

pigment choose the color of a substance

-three things happens to different wavelengths when it shines an object->absorbed, tranmitted, or reflected

-If a color is green, it is green because green is reflected from the object and other color is absorbed

>Identifying Chloroplast pigments

-We can observe different pigments in a green leaf by using laoratory tech called paper chromatography

-paper chromatography can separate and analyze the pigments in a leaf

*Harvesting Light energy

-We can watch the process occuring in a chloroplast as sunlight strikes a leaf.

-photosystems contains pigment molecules-the solar collectors

-Pigment's electrons gains energy as pigment molecules absorbs light energy

-chlorophyll a molecule get trapped by primary electron acceptor to be used to make ATP and NADPH

*Chemical Products of the Light Reactions

-light strikes photosystem and transfer excited electrons to the primary electron acceptor.

-electrons split water and releases oxygen

-excited electron goes through electron transport chain and pumps H+ions across the membrane to thylakoid.

-light excited electrons get ransferred to NADP+

*Concept Check

1.Explain why a leaf appears green

-leaf appears green because it reflects green light and absorb the other light colors

2.Describe what happens when a molecule of chlorophyll a absorbs light.

-when a molecule of chlorophyll a absorbs light it gets trapped by primary electron acceptor to produce ATP and NADPH.

3.Besides oxygen, what two molecules are produced by the light reactions?

-ATP & NADPH

4.Where in the chloroplast do the light reactions take place?

-It takes place in the thylakoid membrane

Concept 8.1 Photosynthesis Uses Light Energy to Make Food

=8.1 Photosynthesis uses light energy to make food=

*Vocab
-chloroplast=> The cellular organelle where photosynthesis takes place.
-chlorophylls=> Chemical compound that give chloroplast to have green color
-Stroma=> thick fluid contained in the inner membrane of a chloroplast.
-Thylakoid=>Disk shaped sac in the stroma of a chloroplast; site of the light
-Light reaction=> The reactions that convert the energy in sunlight to chemical energy
- Calvin cycle=> cycle in plants that makes sugar from carbon dioxide, H+ions, and hight-energy electrons carried by NADPH

*The Structure of Chloroplasts
-All the green parts of the plant contain cells with chloroplasts and carry out photosynthesis
-Leaves has the mot chloroplasts in plants
-Stomatas are pores where CO2 enters and O2 exits
-Chloroplast's inner membrane has stroma, the thick fluid, and thylakoids are suspened in the stroma as disk-shaped sacs.
-Chloroplasts' shape is easy to organize the reaction of phosynthesis

*Overview of Photosynthesis
-Photosynthesis 6CO2+6H2O ->-> C6H12O6+6O2
- There are two main stages in photosynthesis: Light reactions & The Calvin Cycle
*light reactions produce ATP to calvin and get ADP+phosphate from Calvin cycle
*Calvin Cycle produces sugar

*Concept Check
1. Draw and label a simple diagram of a chloroplast that includes the following structures: outer an inner membranes, stroma, thylakoids.
-

2.What are the reactants for photosynthesis? What are the products?
-Reactants: Carbon dioxide & Water
-Products: Glucose & Oxygen

3.Name the two main stages of photosynthesis. How are the two stages related?
- The two main stages are the light reactions and the calvin cycle. Both are related in the way they produce ATP and together, collaborate to produce O2 and Sugar.

Chp6 Vocab List

=Chp6 Vocabs=

organelle-a specific job to do for each part of a cell
plasma membrane- a thin outer covering of cells
nucleus- the center of a cell which houses the cell's genetic material in the form of DNA
cytoplasm- the entire region of the
cell wall- the wall of cell that protects the plant cell and maintains its shape
prokaryotic cell- one kind of cell that lacks a nucleus and most other organelles
eukaryotic cell- another kind of cell that has a nuclus surrounded by its own membrane, and has other internal organelles bounded by membranes.
diffusion- the net movement of the particles of a substance from where they are more concentrated to where they are less concentrated
equilibrium- point at which the number of diffusing molecules moving in one direction is equal to the number moving in the opposite direction
selectively permeable membrane- membrane that allows some substances to pass more easily than others and blocks the passage of some substances altogehter.

Chapter 5 Review

=Reviewing concepts=

1. Which of the following is not an organic molecule?

a. cellulose

b.surcrose

c.water

d. testosterone

answer= c. water

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

a. polysaccharide

b. carbohydrate

c. monosaccharide

d. glycogen

answer= b. carbohydrate

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

a. hydrocarbon

b. hydrophobic

c. hydrophilic

d. organic

answer= c. hydrophilic

4. Cholesterol is an example of what kind of molecule?

a. protein

b. lipid

c. amino acid

d. carbohydrate

answer= b. lipid

5. The 20 amino acids vary only in their

a. carboxyl groups

b. side groups

c. amino groups

d. lipid groups

answer= b. side groups

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

a. catalyst.

b. sucrase

c. active site

d. substrate.

answer= d. substrate

7. An enzyme does which of the following?

a. adds heat to a reaction, speeding it up

b. lowers the activation energy of a reaction

c. cools a reaction, slowing it down

d. raises the activation energy of a reaction

answer= b.

8. Besides satisfying your hunger, why else might you consume a big bowl of pasta the night before a race?

- You need energy before the big race so pasta provides you carbohydrates that will help you run well in the race giving enough energy.

9. How are glucose, sucrose, and starch related?

-They are all made up of monosaccharides.

10.What are steroids? Describe two functions they have in cells.

- Steroid is a lipd molecule in which the carbon skeleton forms four fused rings and the function in circulating in our body as chemical signals and cause the male and female appearances.

11. How are polypeptides related to proteins?

- Polypeptides create all different kinds of proteins.

12. How does denaturation affect the ability of a protein to function?

- Denaturation affect proteins to change their shape and proteins do not function well.

*Applying Concepts

14. Analyzing Diagrams The reaction below shows two amino acids joining together.

a. One product of this reaction is represented by a question mark. WHich molecule is it?

- water molecule

b. WHat is this kind of reaction called? Explain

- Dehydration reaction takes place when a water molecule goes off and form a new bond with other polymers

c. If an amino acid were aded to this chain, at what two places could it attach?

- Amino acid can attach to either to the amino group of carboxyl group

15. Analyzing Graphs Use the graph to answer the questions below

a. At which temperature does enzyme A perform best? Enzyme B?

- Enzyme A: 38 degrees    Enzyme B: 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: human             Enzyme B: thermophilic bacteria

c. Propose a hypothesis that explains why the rate of the reaction catalyzed by enzyme A slows down at temperatures above 40 degrees.

- Even though the temperature is above 40 degrees, the rate of the reaction slows down.  That means the product will be shortly released and the reaction is about the end.

Summary 5.5

=Enzymes are proteins that speed up specific reactions in cells=

*Key terms
activation energy: the 'start-up' energy that activates the reactants and triggers a chemical raaction.
catalysts: compounds that speed up chemical reactions
enzymes: the main catalysts of chemical reactions in organisms that are spcialized proteins
substrate: a specific reactant acted upon by and enzyme
active site: a particular region of enzyme where substrate fits into

*Enzymes and Activation Energy

- Reactions all need activation energy to react and produce a product.
-Ways to provide activation energy: -heat up the mixture of molecules.
-cellular reactions depend on the catalysts.
-specialized proteins called enzymes.
-enzymes help cells to react in its normal tempertaure
-not providing activation energy
-lowers the energy requirement barrier

*How Enzymes Work
-Enzyme fits the shape of only particular reactant molecules
-The fit between enzyme and substrate is snug
- tighter grip may also bend the substrate, weakening its bonds
- lower activation energy by accepting two reactant molecules
-temperature, pH, etc affects enzyme works.

*Concept Check 5.5
1. Explain the role of activation energy in a reaction. How does an enzyme affect activation energy?
- Activation energy is the energy that helps reactants to react. Enzymes catalyze the reaction.
2. Describe how a substrate interacts with an enzyme.
-Subscrate fits into an enzyme and get easily reacted

Summary 5.4

=Protenins perform most functions=

*Key Terms
protein: a polymer constructed from a set of just 20 kinds of monomers called amino acids
amino acid: monomer that makes up proteins; contains carboxyl and amino functional groups.
polypeptide: a chain of proteins linked by amino acids together.
denaturation: loss of normal shape of a protein due to heat or other factor.

*The Functions of Proteins

protein: a polymer by set of just 20 kinds of nomonmers(amino acids).
-functioning of organisms in daily life
ex) hair and fur, amke muscles, and provide nutrient storage
-less visible functions ex) circulate in the blood
fend the body from harmful microorganisms
hers that act as signals
-structure of proteins is the key to understanding their elaborate and diverse functions.

*Amino Acids
amino acid: consists central carbon atom bonded to four partners
- 3 parts are all the same

- one part=>hydrogen atom

- two others are a carboxyl group and amino group

+ 'side group' or 'R-group', the fourth bond of the central carbon, cause the difference about amino acids.

ex) leucine, and serine

*Building Protein

polypeptide: cells create proteins by linking amino acids together into a chain.

- the link is created by a dehydration between amino group of amino acid and the carboxyl group of amino acid in the cahin.

- body createds variety of proteins by arranging different amino acids in different orders.

- most polypeptide chains are at least 100 amino acids in length due to the 20 choices for each amino acid.

- each protein has unique sequence of amino acids.

*Protein Shape

- functional protein has one or more polypeptides precisely twisted, folded, and coiled.

- protein's shpe is also influenced by environment, usually aqueous

-> water attracts hydrophilic side groups and rejects hydrophobic

denaturation: changes in shape of protein due to temperatur, pH,or some other qualities

-ex) egg's white liquid part turning into solid while heating up.

*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 protects our head to be warm.
- Egg's white part is very nutrient

2. Relate amino acids, polypeptides, and proteins.

- Protein is made out of lots of amino acids and polypeptide is a chain that cells created by linking amino aicds. Therefore, amino acid is just a building blocks of these.

3. Explain how heat can destroy a protein.

- Heating up a protein is a change in temperature and that causes protein to unravel and change its shapes

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

- All amino acid has centeral carbon and side groups is the unique part where determines the property of proteins.

5.3 Summary

5.3: Lipids include fats and steroids
*Key terms
-lipids: the compounds that water avoid to be mixed together
-hydrophobic: Water-avoiding molecules

-fat: organic compound consisting of a three-carbon backbone (glycerol) attached to three fatty acids.

-saturated fat: a fat in which all three fatty acid chains contain the maximum possible number of hydrogen atoms

-unsaturated fat: a fat that contains less than the maximum number of hydrogen atoms in one or more of its fatty acid chains.

-steroid: a lipid molecule in which the carbon skeleton forms four fused rings

-cholesterol: an essential molecue found in the membranes that surround our cells.

*Characteristics of Lipids

lipids= water-avoiding compounds ex) fat, oil

hydrophobic= water-avoiding molecules

-other types of lipids 1)stored as fats

2)circulate in our body as chemical signals to cells

*Fats

-three-carbon backbone(glycerol) with three fatty acids

-fats have solid and liquid

-tissues cushion your organs and provide body insulation

-saturated contains maximum possible hydrogen atoms bonded with carbons

ex) butter and animal fats

-unsaturated is less than the maximum # hydrogen atoms cuz of double bonds with carbons

ex) fruiths, vegetables, fish, corn oil, olive oil

*Steroid

- a lipid molecule in which the carbon skeleton forms four fused rings

- hydrophobic like lipids

- steroid estrogen and testosterone functions cause the appearance of male and female.

- the different structure of molecules of testosterone and estrogen

+ Cholesterol: an essential molecule found in the membrances that surround our cells. A tlpe of steroid

- high-level cholesterol increase risk for cardiovascular disease.

Concept Check 5.3

1. WHat property do lipids share?

- Lipids do not want to mix with water. Therefore, lipids act as a boundary that surrounds and contains watery cells.

2. WHat are the parts of a fat molecule?

- Fats consist of a three-caron backbone called glycerol attached to three fatty acids on each part. Fatty acids have long hydrocarbon chains.

3. Describe two ways that steroids differ from fats.

- Steroids differ in structure and function. Steroids circulate in our body as chemical signals. Their estrogen and testosterone cause male and female appearance. In structure, these two types of steroids differ in the location of molecules.

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

- Unsaturated fat means that there are some double bonds on hydrocarbons.