Life 102 (Exam 2- Cellular respiration & Photosynthesis)

Cellular Respiration (Purpose)

Breaks down food (Glucose) to generate ATP for use by the cell.

Glycolysis: Step 1 Of cellular respiration

Location: Cytosol

Input: Glucose

Output: 2 pyruvate, 2 ATP, 2 NADH

No oxygen Required.

Pyruvate Oxidation: Step 2

Location: Mitochondria

Input: 2 pyruvate

Output: 2 Acetyl CoA, 2 Co2, 2 NADH

Requires Oxygen - INDIRECTLY

Citric Acid Cycle: Step 3

Location: Mitochondria

Input: 2 Acetyl CoA

Output: 2 ATP, 6 NADH, 2 FADH, 4 Co2

Requires O2 - INDIRECTLY

Electron Transport Chain: Step 4

Location : Inner Mitochondria; Membrane

Input: O2 Electron from NADH & FADH2

Output: ATP, H2O

Requires Oxygen DIRECTLY

Chemiosmosis- Cellular Respiration

Purpose: Formation of ATP

Location: Inner Mitochondrial membrane

Chemiosmosis

The movement of hydrogen ions down their concentration gradient across a semi- permeable membrane (Through ATP synthase)

Oxidation phosphorylation

The production of ATP using the process of chemiosmosis in mitochondrial.

- hydrogen ions gradient is formed by the electron transport chain is used by ATP synthase to form ATP

Photosynthesis (Purpose)

to utilize energy from the sun to generate sugars for use by the plant cell

Light- Dependent : Step 1 Photosynthesis

Location: Thylakoid membrane

Inputs: H2O, light energy

Outputs: ATP, NADPH, O2

Light- Independent: Step 2

Calvin cycle: Dark reaction

Location: Stroma

Inputs: Co2, ATP, NADPH

Output: Sugar

Carbon Fixation

fixing carbon into an organic molecule such as monosaccharide

Chemiosmosis- Photosynthesis

Location: Thylakoid membrane

Purpose : To use the movement of H+ down their gradient through ATP Synthase to generate ATP for use by the Calvin Cycle

Gibs free energy

Energy available to do work

Spontaneous: Negative

Non-spontaneous: Positive

Delta G

Free energy to change a reaction.

-Determines whether it's spontaneous or non - spontaneous

Activation Energy

The energy required to start any chemical reaction.

-Enzymes lower activation energy

- Enzymes do not change Delta G

Why does Chemiosmosis occur?

There is a difference in the concentration of H+ ions on either side of membrane.

Pigments- Photosynthesis

- Pigment absorb light energy

- Color is determined by the light they do not absorb.

- In plants chlorophyll A & B do not absorb green light .

- Chlorophyll A & B absorb red-orange & blue - violent wavelengths. Green light is reflected.

- Carotenoids do not absorb yellow light, so they yellow.

Thermodynamics Definition

Study of energy on a system

1st Law

_ The energy of the universe is constant

-Can not be destroyed or created

- Can transferred/ transformed

2nd Law

States that energy transformation increased disorder (Entropy)

Catabolic ( Cellular respiration )

Breaking down molecules.

Anabolic (Photosynthesis)

Building up molecules.

Tonicity

Comparison (Inside/outside a cell) across a membrane between 2 solutes

Hypertonic

A solution of higher concentration than a cell

Hypotonic

A solution of lower concentration than a cell

Isotonic

A solution of equal concentration than a cell

Osmosis- Direction, effects of gradients

* Selectively Permeable

* Passive transport

* Movement Of water

- From high to low water concentration

- From low to high solute concentration

Active Transport

Movement of molecule against the concentration gradient

- Requires Cellular energy

Passive transport

Molecules, like water that are able to freely pass through the membrane without the cell using any energy use

Oxidation

- Oxidation always accompanies reduction

- is a chemical process in which a substance:

Loses electrons,

Gains oxygen, or

Loses hydrogen.

reduction

Redox Reaction: is a chemical involving both reduction and oxidation.

-Results in changes in the oxidation numbers of atoms included in the reaction

Light energy to- Wavelength

- Electromagnetic Radiation

- Given off by electrons in an object; moves in the waves .

- Spectrum: different frequencies & wavelengths.

- Long wavelength: Low frequency- low energy

- Short wavelength- High frequency- high energy.

Potential energy

Condensation- Water gain or loss

* Condensation refers to a type of chemical reaction where two molecules are joined together with the loss of a water molecule.

* Water Loss (Anabolic)

Hydrolysis - Water gain or loss

* Hydrolysis is a chemical reaction where a larger molecule is broken down into smaller parts by adding water.

* Water Gain (Catabolic)

Describe enzyme- function, inhibition,

Enzymes Job: Help reaction to occur, Lowering activation energy.

Inhibitors= to regulate pathways/inhibits reaction:

-Competitive: Bind to active site, same as substrate

- Non-competitive (Allosteric) : Bind to other site, not active site.

Photosynthesis photo-systems

* Photosystems are protein-pigment complexes found in the thylakoid membranes of chloroplasts. They are key players in the light-dependent reactions of photosynthesis.

* Photosystem II (PSII)

- First in the sequence, even though it's "II"

- Absorbs light best at P680 nm wavelength

- Splits water (H₂O) to replace lost electrons

- This releases O₂ gas and protons (H⁺)

- Electrons go down the electron transport chain

- Energy from this pumps H⁺ into the thylakoid, making a gradient for ATP production via ATP synthase

Input: Light + H₂O

Output: O₂ + ATP

* Photosystem I (PSI)

-Absorbs light best at P700 nm

-Receives electrons from PSII

-Light excites electrons again

-Passes them to NADP⁺, reducing it to NADPH

Input: Light + electrons from PSII

Output: NADPH

Phosphorylation- ADP/ATP

= Adding a phosphate group

Ex: to ADP to become ATP

ADP: 2 phosphate

ATP: 3 phosphate

Endothermic

- En - enter

- Heat energy is absorbed from the surroundings

Exothermic

Ex- Exits

- Heat energy is released into the surroundings

OIL RIG

- Oxidation is loss of electrons

- Reduction is gain of electrons

Phosphorylation - Substrate lvl

Enzyme transfers phosphate from substrate to ADP to make ATP

oxidative phosphorylation

- Electrons from the reduced cofactors NADH & FADH2 are passed to proteins in the respiratory chain

Calvin Cycle

Light independent- Dark RxN

* Co2 enters through stomata

- Diffuses into stroma

* Uses energy from light reactions

- ATP & NADPH

Cellular Respiration- Equation

Photosynthesis- equation

Properties of phospholipids

* Molecules that have both hydrophilic (water-loving) and hydrophobic (water-fearing) parts.

* The head is hydrophilic (attracted to water).

* The tails are hydrophobic (repel water).

* Bilayer: Self-assembled double layer → forms cell membranes

* Fluidity: Membrane is flexible; affected by tail type, cholesterol, and temperature

Why is a membrane required for chemiomosis?

A membrane is required to create a gradient

Reactants & Products for cellular Respiration

Reactants : O2 + Glucose

Products: H2O + Co2 + ATP

What happens to water in the light- dependent reaction?

It splits into electron, o2 , H+

What provides the energy for the light- dependent reactions?

The sun provides light-energy

What is the CO2 used for in the light - independent reactions

CO2 is fixed into sugars in the Calvin Cycle

Why do plants use both photosynthesis and CR

Plants use cellular respiration to provide energy in the form of ATP of cellular processes & photosynthesis to create sugars for use by the plant.

Endergonic

A chemical reaction that absorbs energy

Exergonic

Chemical reactions that release energy

What happens when there's no oxygen in Pyruvate oxidation

Fermentation occurs and produces NADH +

Electron Transport Chain - equation

E- + H+ + O2 = H2O