Concept Check and Summary 8.2

Summary 8.2

-Chloroplasts like chemical factories, with energy from the sun, coverting it to energy for plants
-Sunlight is a form of electromagnetic energy which travels in waves
-distance between two adjacent waves is called wavelength
-range of types of electromagnetic energy, from short gamma rays to long wavelengths of radio waves is electromagnetic spectrum

-Different forms of electromagnetic energy have different wavelengths, shorter ones have more energy
-visible light are wavelengths that your eyes see as different colors are only a small fraction of thespectrum
-Visible light consists of wavelengths from about 400 nanometers to about 700 nm
-Shorter wavelengths have more energy than longer wavelengths.

-pigments and substance's color is due to chemical compounds called pigments
- light shines on a material that contains pigments: they can be absorbed, transmitted, or reflected
-the chloroplast pigments do not absorb green light well asmost of the green light passes through the leaf (is transmitted) or bounces back (is reflected), looking green because the green light is not absorbed.

-using paper chromotography, you could observe the different pigments in a green leaf

-he pigments dissolve in the solvents and are carried up the strip

-Different pigments travel at different rates, depending on how easily they dissolve and how strongly they are attracted to the paper

-within the thylakoid membrane, chlorophyll and other molecules are arranged in clusters called photosystems which contains a few hundred pigment molecules

-Each time a pigment molecule absorbs light energy, one of the pigment's electrons gains energy becoming very unstable

-Almost immediately,the excited electron falls back to the ground state and transfers the energy to a neighboring molecule, the energy "jumps" from molecule to molecule until it arrives at what is called the reaction center of the photosystem.

-Two photosystems are involved in the light reactions: first photosystem traps light energy and transfers the electrons to an electron transport chain, releases oxygen as a waste product, and also releases hydrogen ions.

- releases energy which the chloroplast uses to make ATP.

-mechanism of ATP production is very similar to ATP production in cellular respiration as electron transport chain pumps hydrogen ions across a membrane

-main difference is that in respiration food provides the electrons for the electron transport chain, while in photosynthesis electrons from chlorophyll travel down the chain.

- second photosystem can be thought of as the "NADPH-producing photosystem."photosystem produces NADPH by transferring excited electrons and hydrogen ions to NADP⁺

Concept Check 8.2

1. Explain why a leaf appears green.

A leaf appears green because the pigments located in the chlorphylls of the leaf do not absorb green light, therefore reflecting and bouncing off the light. When light shines on a material that contains pigments, three things can happen to the different wavelengths: they can be absorbed, transmitted, or reflected. The pigments in the leaf's chloroplasts absorb blue-violet and red-orange light very well. But the chloroplast pigments do not absorb green light well. Most of the green light passes through the leaf (is transmitted) or bounces back (is reflected) as leaves look green because the green light is not absorbed.

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

When a molecule of chlorophyll a which absorbs lightmainly blue-violet and red light and reflects mainly green light, it turns the substance into a green color. Chlorophyll a plays a major role in the light reactions of photosynthesis. Also, chlorphyll a is present in the reaction center which consists of a chlorophyll a molecule located next to another molecule called a primary electron acceptor. The primary electron acceptor is a molecule that traps the excited electron from the chlorophyll a molecule.

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

Besides oxygen, this process also releases hydrogen ions and NADPH molecules.

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

The light reactions take place in both cases across a membrane—the inner mitochondrial membrane in respiration and the thylakoid membrane in photosynthesis.

Concept Check and Summary 8.1

Summary 8.1
-the chloroplasts is the cellular organelle where photosynthesis takes place
-chloroplasts contain chemical compounds called chlorophyll's that give these organelles a green color
-the leaves contain the most chloroplasts and are the site for most photosynthesis
-the chloroplasts are concentrated in the cells of the mesophyll, the inner layer of tissue, within a leaf
-Stomata, the tiny pores on the surface of the leaf letting CO2 enter the leaf and oxygen exit the leaf through this pore
-The veins carry water and nutrients from roots to the leaves delivering organic molecules produced in the leaves to other parts

-This is photosynthesis in cellular organelles

-chloroplast's structure is important like a mitochondria
-Have an inner and an outer membrane with a thick fluid called stroma in inner membrane
-disk-shaped sacs called thylakoids are in the stroma are many
-thylakoids are in stacks, grana


-the opposite of cellular respiration occurs in photosynthesis
-Electrons from water are boosted by the energy from sunlight allowing chlorplasts to use elecrtrons CO2 and hydrogen ions to produce sugar

-Photosynthesis occurs in two main stages: the light reactions and the Calvin cycle

-The light reactions convert the energy in sunlight to chemical energy.

- chlorophyll capture light energy to remove electrons from water splitting into oxygen and hydrogen ions

-oxygen is waste making energy rich products NADPH and ATP.

-The Calvin Cycle makes sugar from carbon dioxide, hydrogen ions and the electrons carried by NADPH

- enzymes for the Calvin cycle are outside the thylakoids, dissolved in the stroma.

-ATP made by the light reactions provides the energy to make sugar

- Calvin cycle does not directly require light to begin

-Calvin cycle requires two inputs supplied by the light reactions, ATP and NADPH.

Concept Check 8.1
1. Draw and label a simple diagram of a chloroplast that includes the following structures: outer and inner membranes, stroma, thylakoids.

http://www.helpsavetheclimate.com/chloroplast1.gif

2. What are the reactants for photosynthesis? What are the products?
The reactants for photosynthesis are 6 Carbon Dioxide molecules and 6 Water molecules. The products are glucose and 6 oxygen molecules.

3. Name the two main stages of photosynthesis. How are the two stages related?
The two main stages of photosynthesis are the light reactions and the Calvin cycle. The two stages are related in that they are both working together to make photosynthesis a possible action and that they both concert sunlight into chemical energy used for plants. These stages both help create ATP using sunlight and the Calvin cycle follows the stage of the light reaction.

Vocabulary Section 8.1-8.2

8.1 Section Vocabulary
Chloroplast: the cellular organelle where photosynthesis takes place
Chlorophyll: A type of chemical compounds that chloroplasts contain, which give these organelles a green color. All green parts visible contain chloroplasts and can carry out photosynthesis
Stroma: A thick fluid of the inner membranes of a chloroplast which has a inner and outer membrane, similar to the mitochondria matrix.
Thylakoids: Suspended in the stroma are many disk-shaped sacs. They each have a membrane surrounding an interior space, arranged in stacks called grana.
Light reactions: Convert the energy in sunlight to chemical energy
Calvin Cycle: makes sugar from the atoms in carbon dioxide plus the hydrogen ions and high energy electrons carried by NADPH. the enzymes for the Calvin cycle are located outside the membrane and dissolved in the stroma.
8.2 Section Vocabulary

Wavelength: the distance between two adjacent wave
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
Pigments: a substance's color is due to chemical compounds
Paper chromatography: a laboratory technique which allows people to observe the different pigments in a green leaf
Photosystems: within the thylakoid membrane, chlorphyll and other molecules are arranged in clusters, each containing a few hundred pigments molecules including chlorphyll.

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.

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.

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 called glycerol attached to three fatty acids, which contain long hydrocarbon chains
-Some fats are solid at room temperature while others 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 hydrogen 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.