Textbook Notes (378,370)
US (209,719)
UI (814)
IB (6)
IB 103 (2)
Jacobs (2)
Chapter

Photosynthesis Light-Dependent Reactions.docx

8 Pages
94 Views

Department
Integrative Biology
Course Code
IB 103
Professor
Jacobs

This preview shows pages 1-3. Sign up to view the full 8 pages of the document.
Energy Part 1, Lecture 2: Photosynthesis: Light-Dependent Reactions
Pgs 25-27, 38-41, 66-76
Chemical Background Information (pgs 25-27)
Electrons move around nucleus, but their exact positions are uncertain
- The electron configuration of an atom is the way electrons are arranged around nucleus
- Electrons are negatively charged; nucleus is positive
- Electrons and nucleus attract each other while electrons vs electrons repel each other
- Energy levels:
o 1: closest to nucleus, 2 electrons to be „complete‟
o 2: max.of 8 electrons, 8 to be „complete‟
o 3: more than 8 electrons, 8 to be „complete‟
o 4: more than 8 electrons, 8 to be „complete‟
- Electron with more energy (ex:light energy) allows it to move farther from nucleus;
giving up energy allows it to drop to lower energy level)
Chemical bonds hold atoms together
- Compounds are fixed ratios of united elements (H2O)
- Chemical bond is the force holding 2+ atoms together in a compound
- Main point: if atom‟s outer energy level is less than 8 electrons, it gains, loses, or shares
them to reach 8 (except hydrogen and helium)
- This is done through ionic and covalent chemical bonds
Atoms gain or lose electrons to form ionic bonds
- ion is a gain or loss of electrons in an atom
- an ionic bond is the force of attraction between 2 oppositely charged ions
- ex: NaCl (sodium chloride)
Atoms share electrons to form covalent bonds
- covalent bond is when 2 atoms share electrons to complete outer energy levels
- molecules are formed by 2 or more covalent bonds
- example: methane (CH4)
- sharing one pair of electrons= single bond; sharing two pairs =double bonds
- nonpolar covalent bonds are covalent bonds which equally share electrons (ex:H2), and
unequally shared is polar covalent bonds
Hydrogen bonds are attractions between adjacent molecules
- hydrogen bond= positively charged H atom in one polar molecule and a negatively
charged O or N atom in another polar molecule
- Weak bonds compared to covalent
- Form and break easily
- Affects shape and function of protein and nucleic acid molecules
- Determines properties of water
Biological Background Information (pgs 38-41)
Enzymes and Activation energy
- Enzymes catalyze reactions, therefore less activation energy needed
- Enzyme performs reaction on substrate, increasing rate of reaction
Enzyme+ substrate(s)enzyme-substrate complexenzyme + product(s)
Substrates find active sites on enzyme and react with each other, and products separate from
enzyme so enzyme is used for other substrates
DNA and RNA are nucleic acids
- Nucleic acids are macromolecules containing O, H, N, and P elements
- DNA (deoxyribonucleic acid) contains instructions for making necessary proteins;
instructions are written in genes, the unit of hereditary info
- DNA molecule is a double helix
- RNA helps for protein synthesis
- Nucleotides are the repeating units in nucleic acids
- One nucleotide= nitrogenous base, 5-carbon sugar, and phosphate molecule
Energy is temporarily stored in ATP
- Nucleotides don‟t just build nucleic acids: some serve other functions
- ATP (Adenosine triphosphate) is a nucleotide containing: base adenine, sugar ribose, and
3 phosphate molecules
- “energy currency” present in all living cells
- Transfers energy
Energy and Biological Work
- Energy is the ability to do work
- Different forms: chemical (in molecular bonds), heat, radiant (sun), mechanical, electrical
- Stored energy= potential energy
- Energy in motion = kinetic energy
The laws of thermodynamics govern energy transformations
- thermodynamics is the study of energy and its transformations
- Law 1: First Lawenergy cannot be created or destroyed
- Plants can‟t simply create energy to live, but must capture from the environment
- Law 2: Second Lawwhen energy is converted from one form to another, some of it is
degraded into a lower-quality, less useful form
- Entropy is a measure of the disorder in energy.
- Organized/usable energy (electrical, chemical) have low entropy (disorder)
- Heat= disorganized energy, so high entropy
Chapter 4:Metabolism in Cells, Photosynthesis (pgs 66-76)
Metabolism
- Metabolism is known as the chemical processes occurring in the cell
- 2 kinds of chemical rxns in cell‟s metabolism:
1. Anabolic reactions (anabolism)energy stored in molecules
- Large molecules synthesized from simpler molecules
- „building-up‟ process
- In photosynthesis, CO2 and H2O creae glucose
2. Catabolic reactions (catabolism)energy is released from molecules
- Break down process
- Large molecules split apart into simpler ones to release energy
- In cellular respiration of glucose, it is broken down to CO2 and H2O with the
release of energy
Oxidation-reduction reactions occur in metabolism
- Electrons are the means of transferring energy in cells
Oxidationchemical process where substance loses electrons
Reductionchemical process reaction where substance gains electrons
- Both rxns accompany each other
- If substance gains electron (through reduction), the electron had to have been
lost in oxidation rxn
- O-R rxns are in photosynthesis

Loved by over 2.2 million students

Over 90% improved by at least one letter grade.

Leah — University of Toronto

OneClass has been such a huge help in my studies at UofT especially since I am a transfer student. OneClass is the study buddy I never had before and definitely gives me the extra push to get from a B to an A!

Leah — University of Toronto
Saarim — University of Michigan

Balancing social life With academics can be difficult, that is why I'm so glad that OneClass is out there where I can find the top notes for all of my classes. Now I can be the all-star student I want to be.

Saarim — University of Michigan
Jenna — University of Wisconsin

As a college student living on a college budget, I love how easy it is to earn gift cards just by submitting my notes.

Jenna — University of Wisconsin
Anne — University of California

OneClass has allowed me to catch up with my most difficult course! #lifesaver

Anne — University of California
Description
Energy Part 1, Lecture 2: Photosynthesis: Light-Dependent Reactions Pgs 25-27, 38-41, 66-76 Chemical Background Information (pgs 25-27) Electrons move around nucleus, but their exact positions are uncertain - The electron configuration of an atom is the way electrons are arranged around nucleus - Electrons are negatively charged; nucleus is positive - Electrons and nucleus attract each other while electrons vs electrons repel each other - Energy levels: o 1: closest to nucleus, 2 electrons to be „complete‟ o 2: max.of 8 electrons, 8 to be „complete‟ o 3: more than 8 electrons, 8 to be „complete‟ o 4: more than 8 electrons, 8 to be „complete‟ - Electron with more energy (ex:light energy) allows it to move farther from nucleus; giving up energy allows it to drop to lower energy level) Chemical bonds hold atoms together - Compounds are fixed ratios of united elements (H2O) - Chemical bond is the force holding 2+ atoms together in a compound - Main point: if atom‟s outer energy level is less than 8 electrons, it gains, loses, or shares them to reach 8 (except hydrogen and helium) - This is done through ionic and covalent chemical bonds Atoms gain or lose electrons to form ionic bonds - ion is a gain or loss of electrons in an atom - an ionic bond is the force of attraction between 2 oppositely charged ions - ex: NaCl (sodium chloride) Atoms share electrons to form covalent bonds - covalent bond is when 2 atoms share electrons to complete outer energy levels - molecules are formed by 2 or more covalent bonds - example: methane (CH4) - sharing one pair of electrons= single bond; sharing two pairs =double bonds - nonpolar covalent bonds are covalent bonds which equally share electrons (ex:H2), and unequally shared is polar covalent bonds Hydrogen bonds are attractions between adjacent molecules - hydrogen bond= positively charged H atom in one polar molecule and a negatively charged O or N atom in another polar molecule - Weak bonds compared to covalent - Form and break easily - Affects shape and function of protein and nucleic acid molecules - Determines properties of water Biological Background Information (pgs 38-41) Enzymes and Activation energy - Enzymes catalyze reactions, therefore less activation energy needed - Enzyme performs reaction on substrate, increasing rate of reaction Enzyme+ substrate(s)enzyme-substrate complexenzyme + product(s) Substrates find active sites on enzyme and react with each other, and products separate from enzyme so enzyme is used for other substrates DNA and RNA are nucleic acids - Nucleic acids are macromolecules containing O, H, N, and P elements - DNA (deoxyribonucleic acid) contains instructions for making necessary proteins; instructions are written in genes, the unit of hereditary info - DNA molecule is a double helix - RNA helps for protein synthesis - Nucleotides are the repeating units in nucleic acids - One nucleotide= nitrogenous base, 5-carbon sugar, and phosphate molecule Energy is temporarily stored in ATP - Nucleotides don‟t just build nucleic acids: some serve other functions - ATP (Adenosine triphosphate) is a nucleotide containing: base adenine, sugar ribose, and 3 phosphate molecules - “energy currency” present in all living cells - Transfers energy Energy and Biological Work - Energy is the ability to do work - Different forms: chemical (in molecular bonds), heat, radiant (sun), mechanical, electrical - Stored energy= potential energy - Energy in motion = kinetic energy The laws of thermodynamics govern energy transformations - thermodynamics is the study of energy and its transformations - Law 1: First Law—energy cannot be created or destroyed - Plants can‟t simply create energy to live, but must capture from the environment - Law 2: Second Law—when energy is converted from one form to another, some of it is degraded into a lower-quality, less useful form - Entropy is a measure of the disorder in energy. - Organized/usable energy (electrical, chemical) have low entropy (disorder) - Heat= disorganized energy, so high entropy Chapter 4:Metabolism in Cells, Photosynthesis (pgs 66-76) Metabolism - Metabolism is known as the chemical processes occurring in the cell - 2 kinds of chemical rxns in cell‟s metabolism: 1. Anabolic reactions (anabolism)—energy stored in molecules - Large molecules synthesized from simpler molecules - „building-up‟ process - In photosynthesis, CO2 and H2O creae glucose 2. Catabolic reactions (catabolism)—energy is released from molecules - Break down process - Large molecules split apart into simpler ones to release energy - In cellular respiration of glucose, it is broken down to CO2 and H2O with the release of energy Oxidation-reduction reactions occur in metabolism - Electrons are the means of transferring energy in cells Oxidation—chemical process where substance loses electrons Reduction—chemical process reaction where substance gains electrons - Both rxns accompany each other - If substance gains electron (through reduction), the electron had to have been lost in oxidation rxn - O-R rxns are in photosynthesis - Electrons associated with hydrogen are transferred to electron acceptor molecules - In cells, oxidation involves removal of H atom - when H atoms are removed from organic compound and take energy to store in electrons, called Electron acceptor molecules - electron transport chain moves electrons from one acceptor to another Photosynthesis - plants, algae, and certain prokaryotes can absorb and convert light energy from sun into chemical energy in photosynthesis - end products= carbs and oxygen - biomass is organic material used as fuel; wood, agricultural waste, which contains chemical energy traced back to solar energy Light exhibits properties of both waves and particles - light makes up portion of electromagnetic spectrum—the range of radiations through space and matter - gamma rays are short in wavelengths, as opposed to radio waves, which are longest - visible spectrum is the portion of the spectrum humans can see (includes colors) - UV radiation is invisible to human eye, and is shorter in wavelength than visible light - Photons—the small particles of energy that make up light - Shorter wavelength of light=more energy per photon, so inversely proportional - *photosynthesis depends on visible light because it is the perfect length to excite biological molecules. Long waves (ex:microwaves) don‟t have enough energy, and short waves (UV) have too much energy - The ground state is the lowest energy state an electron possesses, but energy can make it higher, so the electron is energized by energy - Molecules are energized when they
More Less
Unlock Document


Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit