LC bio - photosynthesis/respiration/energy carriers

What does atp stand for

adensosine triphosphate

What does adp stand for

adenosine diphosphate

Role of atp

Store energy temporarily

release energy for cellular processes

Processes that use atp in cells

Photosynthesis/mitosis

Advantage of using atp as an energy store

• can be broken down easily

• readily available and can be reused

• high energy molecule

Role of nadh/nadph

Transfer of two electrons and a proton from different stages of photosynthesis and respiration

Photosynthesis

process by which plants make their own food

Where does photosynthesis occur

Chloroplasts

Role of photosynthesis

• make food for plants and animals

• oxygen produced is used in respiration

• Remove co2 from air

Equation for photosynthesis

Carbon dioxide + water + light -> oxygen + glucose

Requirements for photosynthesis

Carbon dioxide, water, light energy, chlorophyll

Where do plants get co2

External atmosphere, absorbed through stomata, internally from plant respiration

Carbon sink

Any system absorbing more carbon dioxide than it releases

Where do plants get water

Soil

Where do plants get light

Sunlight or artificial light

End products of photosynthesis

Glucose and oxygen

General events of photosynthesis

Stage one (light is absorbed, water is split, light energises electrons)

stage two (glucose is formed)

Two stages of photosynthesis names

Light dependent and dark stage

Main events of stage one of photosynthesis

Absorption of photons of light, light energy is transferred to electrons, high energy electrons are passed through two pathways

Describe photolysis

Some of the light energy absorbed is used to split water into oxygen, protons and electrons

Products of photoslysis

• 4 hydrogen ions

• 4 electrons

• o2

What are the protons from photolysis used for

Convert nadp into nadph

Where are the two electron pathways located

Thylakoid membranes

What is the benefit of having clusters of chlorophyll exist

More light absorption and wider ranger of colours absorbed (increase rate of photosynthesis)

What happens in the cyclic pathway

Electron passes from carrier to carrier before returning back to reaction centre chlorophyll
Energy is released as the electron moves
Energy used to join adp+p to form atp

What happens in the non cyclic pathway

Two electrons pass from carrier to carrier
They do not return to reaction centre chlorophyll
As they move from carrier to carrier, they release energy that is used to join adp+p into atp

at the end, low energy electrons join with nadp+ forming nadp-

proton from the proton pool attracted to nadp-, they join to form nadph

End products of light dependent stage

Waste oxygen, atp, nadph

What is the dark stage

Stage two of photosynthesis, takes place in the stroma and is controlled by enzymes

Describe the events of stage two of photosynthesis

Carbon dioxide is converted into glucose
Atp breaks down into adp+p releasing energy
Energy is used to make the larger glucose molecule
Nadph breaks down into nadp+, two electrons and a proton

these protons and electrons are used to make the glucose

Use of glucose

• respiration

• build starch from storage

Differences between light and dark stage

Light needs light to occur, dark can happen either way

enzymes are required for dark but not for light

Use of the light stage

Energize electrons to form atp and nadph

Use of dark stage

Make glucose

End products of the light stage

Oxygen, atp and nadph

End products of dark stage

glucose

Independent variable in the photosynthesis experiment

Light intensity

Dependent variable in photosynthesis experiment

Rate of photosynthesis

Controlled variables in photosynthesis experiment

Amount of elodea, temperature

How is the independent variable changed in this experiment

Light source moved away

Why is elodea used in the photosynthesis experiment

Aquatic plant helps visualise the rate of photosynthesis

What is the purpose of the sodium hydrogen carbonate in the photosynthesis experiment

To supply co2

How is the rate of photosynthesis meausred in its experiment

By counting the bubbles produced in a set amount of time

Why is the water bath kept at 25 celcius

Optimum temperature for plants for photosynthesis

Role of nadp+ in light independent reactions

Combines with two electrons and a proton to form nadph, which supplies electrons and protons to form glucose

What does the energy made in the cyclic pathway do

Combine adp+p into atp

Respiration

The release of energy from food

Who does aerobic respiration happen in

Humans animals and plants

Products of aerobic respiration

Carbon dioxide and water and energy

Does aerobic or anaerobic respiration yield more energy

Aerobic

Products of anaerobic respiration

Lactic acid/carbon dioxide and ethanol

Equation for aerobic respiration

glucose + oxygen → carbon dioxide + water + energy

Source of glucose for aerobic respiration

Plants make it in respiration, animals consume plants/other aniamls

Source of oxygen for aerobic respiration

Atmosphere/photosynthesis

Products of photosynthesis

Co2, water and oxygen

Fate of co2 after respiration

• transported to lungs via plasma and exhaled

• stomata passes it back in atmosphere or is used in photosynthesis

Advantage of atp

Readily available energy source that can be used for muscle contraction, cell repair, cell division etc

Why is respiraton a catabolic reaction

Larger molecules are broken down into smaller molecules, releasing energy

What is meant by aerobic respiration

Release of energy from food using oxygen

Function of aerobic respiration

Produce atp, providing energy for cellular activities

Balanced chemical equation for respiration

C6H12O6 + 6O2 --> 6CO2 + 6H2O + energy

Main events in respiration

• glucose is broken down into a series of enzyme controlled reactions

• energy is released and used to make atp

• co2 and water are produced as waste products

First stage of respiration name

glycolysis

Where in the cell does the first stage of respiration occur

In the cytosol

What is the 6 carbon molecule required for stage one of respiration

Glucose

What hapens to this 6 carbon molecule in stage one

Broken down into two pyruvate

What is released when the 6 carbon molecule is broken down into the three carbon molecules

Small amount of energy, some of which is used to produce atp

What happens after glycolysis if oxygen is present

Pyruvate enters the mitochondria, and is broekn down into acetyl coenzyme a

Where in the cell does the second stage of aerobic respiration take place

Mitochondria (matrix and inner membrane)

What is the name of the 2 carbon molecule that enters the krebs cycle

Acetyl coenzyme a

What products are released from the breakdown of the two carbon molecule in the krebs cycle

Co2, atp nad nadh

What does nadh stand for

Nicotinamide Adenine Dinucleotide with Hydrogen

What is required for the electron transport system

NADH (provides electrons to enter the chain)

Where are the electron transport chains located

Inner mitochondrial membrane (cristae)

What is produced in the electron transport system

Atp, water

How is atp and water formed in the ets

• electrons pass along carriers

• energy is used to produce atp

• oxygen accepts electron and hydrogen ions to form water

What is the function of atp synthase

Uses energy to produce atp from adp and phosphate

Where in the mitochondria would you find atp synthase

Inner mitochondrial membrane

What is the final electron acceptor in the electron transport system

Oxygen

What happens to most of the atp produced

Used immediately by the cell

Name two activities that atp can be used for in the cell

Muscle contraction

What is meant by the term fermentation

Release of energy from food without oxygen

Whats the difference between the types of anaerobic respiration

Depends on the organism

Name the two types of anaerobic respiration

lactic acid fermentation and alcoholic fermentation

First stage of anaerobic respiration

Glycolysis

What happens if oxygen is not present following glycolysis

Pyruvate cant enter mitochondria and will convert to other end products depending on the organism in the cytosol,

Lactic acid fermentation equation

glucose --> lactic acid + energy

Biotechnology

Use of living things or their components to manufacture products

Summery of pre citric acid cycle

If o2 is present, pyruvate moves into mitochondria and is converted into acetyl coenzyme a and co2

What happens to acetyl coenzyme a in the citric acid cycle

Turned into co2, atp and nadh

Summarise the electron transport chain

Nadh moves to electron transport chain in the inner membrane
Nadh releases two electrons and a proton to form nad+
Two electrons move from carrier to carrier, releasing energy

released energy pumps protons from matrix to area between membranes

kinetic energy formed converts adp+p into atp using atp synthase

What is adp made of

Adenosine, ribose and phosphates

Nadp+ stands for

Nicotinamide adenine dinucleotide phosphate

Role of nadh/nadph

Transfer two high energy electrons and a proton from different stages of respiration and photosynthesis