Cellular Respiration and Photosynthesis

Mehr dazu

Organigram

von Samantha Sonntag

Cell Membrane

von Rather Sufyan

Chloroplast

von Emma Spence

Metabolism

von True Jarrel [STUDENT]

Cellular Respiration and Photosynthesis

Connections

Complications

In cellular respiration, if the body does not produce ATP properly, the body will not function

Basic bodily functions will become a challenge, exhaustion will become common and death is possible

In photosynthesis if the weather is too hot, photorespiration occurs

This is a problem because the production of carbohydrates decreases

Can also be decreased using CAM plants which store water and allow for proper functioning

This is decreased using C4 photosynthesis (using C4 plants: less photo respiration and more sugar production)

Ways to make ATP

In Cellular Respiration:

Oxidative Phosphorylation: indirectly forms ATP by using a number of redox reactions

Substrate level phosphorylation: ATP is formed directly in the enzyme catalyzed reaction and a phosphate group is removed and combined with ADP to make ATP

In Photosynthesis:

Absorbed light and energy is used to drive electrons from water to generate NADPH/drive protons across a membrane - these protons go through ATP synthase and make ATP

Reaction Types

Both are considered metabolic reactions/processes

CR is a catabolic reaction which breaks down molecules to make them even smaller

PS is an anabolic reaction which builds complex molecules from small molecules

Vital for Survival

Both CR and PS produce energy and living things must do at least one of them for survival

The processes

ETC

In cellular respiration: the Krebs cycle breaks down glucose

hydrogen carriers (NADH and FADH2) release electrons for the ETC

Electrons from the ETC are taken up by

In photosynthesis: water is broken down into oxygen for electrons

Electrons from the transport chain are moved using electron molecules/carriers

Calvin cycle is used to make glucose

Relationship

They are interdependent to one another to complete their own functions

One cannot occur without the other

Both processes occur in a mututally benficial releationship

Both of these processes occur in different stages

Cellular Respiration: glycolysis, pyruvate oxidation, krebs cycle and etc/chemiosmosis

Photosynthesis: light reactions and the calvin cycle (light dependant and light independent)

Substances

Each process has similar substances involved but at different parts

The products and reactants are flipped (Products of PS are reactants of CR and vice versa) - but energy type varies (sun/ATP)

Reaction Coupling

The glucose and O2 created in photosynthesis is used during cellular respiration to make CO2 and water

This shows that these reactions are coupled as they have common substances

Redox Reactions

In cellular respiration, electrons transfer from glucose molecules to oxygen

In photosynthesis, electrons travel from water to carbon dioxide

Each process can occur in the light but cellular respiration does not require it

Water

Cellular respiration produces water

Photosynthesis uses water

Where?

Although each process is in different organelles, each takes place inside cells

CR is in the cytoplasm and mitochondria

PS is within the chloroplast

When?

Each of these processes is continuously happening for organisms to survive

Plants

Photosynthesis and cellular respiration can both occur in plants but photosynthesis is not possible in animals

CO2

In cellular respiration, carbon dioxide is released into the atmosphere

In photosynthesis, carbon dioxide is removed from the atmosphere

both use this process similarly

Uses the energy in a hydrogen ion gradient to make ATP

Photosynthesis uses light energy to release ATP.

In cellular respiration food is converted into ATP

ATP (the energy both processes create!)

In cellular respiration: ATP is produced by breaking down organic molecules themselves

In photosynthesis: ATP is produced using light energy and it is used to produce organic molecules

Photosynthesis

2. Calvin Cycle: Carbon dioxide and energy from ATP/NADPH produce glucose

1. Light Reactions: Light energy and water produce ATP and NADPH

Electron Carriers

NADPH

Source of Energy

Sunlgiht

Light

Light is not absorbed by individual pigment molecules, it is absorbed by photosystems

Photosystems in photosynthesis

PSII (P680): Chlorophyll A absorbs wavelength of 680nm

PSI (P700): Chlorophyll A absorbs wavelength of 700nm

They contain

Reaction Centre: absorbs light energy and releases excited electrons to primary electron acceptors to start the light reactions

Antenna complex: chlorophyll molecules which collect/channel energy and allows energy ti go to reaction centre

Made of chlorophyll, accessory pigments and proteins

Located in thylakoid membranes

Pigment molecules are used to absorb visible light and appear as the colour of their light wavelength

The action spectrum shows effectiveness of wavelengths promoting photosynthesis

The absorbance spectrum shows the amount of light different wavelengths can absorb

Photons are the energy that travels in waves

Each wavelength is associated with a different color on the electromagnetic spectrum

Necessary for photosynthesis to occur

Other aspects

Anabolic: builds molecules that are needed

Two sets of reactions make up photosynthesis

Light-independent reaction

Energy of ATP and reducing power of NADPH are used to make an organic molecule which is high in energy

Light-dependent reaction

Light energy is trapped and used to generate ATP and NADPH

When a plant is low on water/NAD+ it goes through cyclic phosphorylation (just temporary phase)

Concentration gradient powers ATP synthase by pumping protons down their concentration gradient

Still produce PMF for the protons to move and continue the process

Electrons in PS I pass backwards to cytochrome

Affected by various aspects of the environment for example amount of water, temperature and light intensity

ATP synthase complex drives the phosphorylation of ADP to ATP

This is called photophosphorylation as light is required for it to occur

ATP synthase provides pathway to move down concentration gradient

Hydrogen ions in the thylakoid layer cannot diffuse through membrane

6CO2+6H2O=C6H12O6+6O2

Products: sugars and oxygen

Reactants: carbon dioxide, water and sunlight

ONLY in plant cells (autotrophs)

Within the chloroplast

Chlorophyll is found within the chloroplast

Cartenoids (orange and yellow pigments) can be used to absorb light

They lose this energy through heat

Mainly absorb light which would damage the chlorophyll

2 types

B: Aldehyde group: absorbs photons that A did not absorb properly (-COH attached to ring)

A: Methyl group: primary light absorbing pigment (CH3 is attached to ring)

Made up of a porphyrin ring and a long hydrocarbon tail

Absorbs light to begin the photosynthesis process

The green pigment

Chloroplast is a 2 layered membrane (stroma and thylakoid)

Thylakoids: the layer of membrane bound sacs

Stroma: the fluid-filled interior layer which surrounds the grana

Plants have 40-200 chloroplasts

Synthesizing carbohydrates (ex. glucose) using energy from the sun

Captures energy

Produces food

Cellular Respiration

Source of energy

Glucose

Electron shuttles

Aspartate Shuttle

Transfers electrons to NAD+

Forms NADH and produces ATP

Glycerol-Phosphate Shuttle

Transfers electrons from cytosolic NADH to FAD to produce FADH

very common

Stages

4. Electron Transport Chain: Energy from the NADH and FADH2 is used to produce ATP, Water, NAD+ and FAD

3. Krebs Cycle: Acetyl-CoA and carbon molecules are used to generate NADH, CO2, FADH2 and ATP

2. Pyruvate Oxidation: Pyruvate molecules break down into Acetyl-CoA and CO2 is produced

1. Glycolysis: Glucose and ATP produce pyruvate molecules, NADH and ATP

During this stage substrate level phosphorylation occurs

Which is a process where a phosphate group is removed from a substrate molecule

The group is then combined with ADP to form ATP

ATP

To make ATP energy is required

To release energy, ATP loses a phosphate group

ATP=ADP+inorganic phosphate+energy

Used for cellular processes that require energy

Important Players

FADH2: flavin adenine dinucleotide

NADH: nicotinamide adenine dinucleotide

Other Aspects

Catabolic: breaks down complex molecules for the organism to use

Does not need oxygen to occur ( can be anaerobic)

Electron Transport Chain and Chemiosmosis

Chemiosmosis

New ATP is moved to cytoplasm by facilitated diffusion where it is used to drive reactions requiring energy

Energy is used to phosphorylate ADP to form ATP through oxidative phosphorylation

Energy is released

H+ moves into the matrix through ATP synthase

ETC: the redox reactions that move electrons along the membrane of the mitochondria

Equation

C6H12O6+6O2=6CO2+6H2O+Energy(ATP)

Prodcuts: cardon dioxide, water and energy (ATP)

Reactants: suagrs and oxygen

Where does it occur?

Used in all eukaryotes (autotrophs or heterotrophs)

Begins in the cytoplasm, more specifically moves onto the mitochondria

ETC/Chemiosmosis (oxidative phosphorylation) occur in the inner mitochondrial membrane

Krebs cycle occurs in the mitochondrial matrix

Pyruvate oxidation occurs in the mitochondrial matrix

Glycolysis occurs in the cytoplasm

Purpose

the process used by the cells in plants and animals to break down sugar and turn it into energy to use at the cellular level

Releases energy

Breaks down food