Photosynthesis
All cells need energy to carry out their functions, such as making proteins and transporting substances into and out of the cell
Plants and other organisms such as algae and some bacteria, use energy in sunlight to make their own food
Photosynthesis – the process by which a cell captures energy in sunlight and uses it to make food
Nearly all living things obtain energy either directly or indirectly from the energy of sunlight captured during photosynthesis
Grass obtains energy directly from the sunlight because it makes its own food through photosynthesis. Then the zebra eats the grass; it gets energy that has been stored in the grass. Lastly, the lion gets energy that has been stored in the zebra – the zebra and lion obtain the sun’s energy indirectly
An organism that can make its own food is called an autotroph and an organism that cannot manufacture its own food is called a heterotroph
The Two Stages of Photosynthesis!
During photosynthesis, plants and some other organisms use energy from the sun to convert carbon dioxide and water into oxygen and sugars
Stage 1: Capturing the Sun’s Energy
· This process occurs mostly in the leaves – the green color comes from the pigments, which are colored chemical compounds that absorb light (chloroplasts are the green organelle inside plant cells)
o The main photosynthetic pigment in chloroplasts is chlorophyll!
Stage 2: Using Energy to Make Food
· Next, the cell uses the captured energy to produce sugars - the cell needs two raw materials for this stage – Water (H2O) & Carbon Dioxide (CO2)
1. The root absorbs water from the soil
2. Then the water moves up through the plant’s stem to the leaves
3. Carbon Dioxide enters the plant through the small openings on the underside of the leaves called the stomata
4. Once in the leaves, the water and carbon dioxide move into the chloroplasts
· Inside the chloroplasts, the H2O and CO2 undergo a complex series of chemical reactions – the rxns are powered by the energy captured in the first stage!!
Oxygen (O2) and Six-carbon sugars (C6H12O6) are produced!
Almost ALL of the oxygen in the Earth’s air was produced by living things through the process of photosynthesis!
Photosynthesis Equation:
Light Energy
6 CO2 + 6 H2O - - - - - - - -> C6H12O6 + 6 O2
Carbon Dioxide Water A Sugar Oxygen
Which two are the reactants?
Which two are the products?
Respiration
Respiration – is the process by which cells obtain energy from glucose
During respiration, cells break down simple food molecules such as sugar and release the energy they contain
· During photosynthesis, plants capture energy from sunlight and “save” it in the form of carbohydrates (sugars & starches)
· When your cells need energy, they breakdown the carbohydrates (sugars & starches) in the process of respiration
The Two Stages of Respiration:
1st Stage –
· takes place in the cytoplasm of the organelle’s cells
· molecules of glucose are broken down into smaller molecules
**Oxygen is NOT involved!!!**
2nd Stage –
· takes place in the mitochondria
· the molecules are broken down into even smaller molecules – these chemical reactions require oxygen
**Mitochondria are sometimes called the “powerhouse” of the cell because they release a great deal of energy in stage 2!!**
When you breathe in, you take in oxygen (a material for respiration) and when you breathe out, you release carbon dioxide and water (products of respiration)
The Respiration Equation:
C6H12O6 + 6 O2 - - - - - - - -> 6 CO2 + 6 H2O + energy
A sugar Oxygen Carbon Dioxide Water
Raw materials for respiration are sugar and oxygen. Plants and other organisms that undergo photosynthesis make their own sugar
Meanwhile, glucose in the cells of animals and other organisms comes from the food they consume
Together, photosynthesis and respiration form a cycle that keeps the levels of oxygen and carbon dioxide fairly constant in Earth’s atmosphere – living things use both gases over and over again!
Fermentation – an energy-releasing process that does NOT require oxygen!! - single-celled organisms that live where there is no oxygen, such as in the ocean or in the mud of lakes swaps, obtain energy without using oxygen!
The amount of energy released from each sugar molecule during fermentation is much lower than the amount released during respiration
Alcohol Fermentation – this occurs when yeast and other single-celled organisms break down sugars – it’s called alcohol fermentation because alcohol is one of the products; the other products are CO2 and a small amount of energy
Alcohol fermentation is important for bakers and brewers – the CO2 produced by yeast creates air pockets in bread dough, causing it to rise!
Ever run as fast as you could, in a race? What occurs?
Lactic Acid Fermentation – this takes place in your body! It occurs when your muscle cells use up the oxygen faster than it can be replaced, and since your cells lack oxygen, fermentation occurs – one product of this fermentation is acid and when it builds up, you feel a painful sensation in your muscles – your muscles feel weak and sore!
All cells need energy to carry out their functions, such as making proteins and transporting substances into and out of the cell
Plants and other organisms such as algae and some bacteria, use energy in sunlight to make their own food
Photosynthesis – the process by which a cell captures energy in sunlight and uses it to make food
Nearly all living things obtain energy either directly or indirectly from the energy of sunlight captured during photosynthesis
Grass obtains energy directly from the sunlight because it makes its own food through photosynthesis. Then the zebra eats the grass; it gets energy that has been stored in the grass. Lastly, the lion gets energy that has been stored in the zebra – the zebra and lion obtain the sun’s energy indirectly
An organism that can make its own food is called an autotroph and an organism that cannot manufacture its own food is called a heterotroph
The Two Stages of Photosynthesis!
During photosynthesis, plants and some other organisms use energy from the sun to convert carbon dioxide and water into oxygen and sugars
Stage 1: Capturing the Sun’s Energy
· This process occurs mostly in the leaves – the green color comes from the pigments, which are colored chemical compounds that absorb light (chloroplasts are the green organelle inside plant cells)
o The main photosynthetic pigment in chloroplasts is chlorophyll!
Stage 2: Using Energy to Make Food
· Next, the cell uses the captured energy to produce sugars - the cell needs two raw materials for this stage – Water (H2O) & Carbon Dioxide (CO2)
1. The root absorbs water from the soil
2. Then the water moves up through the plant’s stem to the leaves
3. Carbon Dioxide enters the plant through the small openings on the underside of the leaves called the stomata
4. Once in the leaves, the water and carbon dioxide move into the chloroplasts
· Inside the chloroplasts, the H2O and CO2 undergo a complex series of chemical reactions – the rxns are powered by the energy captured in the first stage!!
Oxygen (O2) and Six-carbon sugars (C6H12O6) are produced!
Almost ALL of the oxygen in the Earth’s air was produced by living things through the process of photosynthesis!
Photosynthesis Equation:
Light Energy
6 CO2 + 6 H2O - - - - - - - -> C6H12O6 + 6 O2
Carbon Dioxide Water A Sugar Oxygen
Which two are the reactants?
Which two are the products?
Respiration
Respiration – is the process by which cells obtain energy from glucose
During respiration, cells break down simple food molecules such as sugar and release the energy they contain
· During photosynthesis, plants capture energy from sunlight and “save” it in the form of carbohydrates (sugars & starches)
· When your cells need energy, they breakdown the carbohydrates (sugars & starches) in the process of respiration
The Two Stages of Respiration:
1st Stage –
· takes place in the cytoplasm of the organelle’s cells
· molecules of glucose are broken down into smaller molecules
**Oxygen is NOT involved!!!**
2nd Stage –
· takes place in the mitochondria
· the molecules are broken down into even smaller molecules – these chemical reactions require oxygen
**Mitochondria are sometimes called the “powerhouse” of the cell because they release a great deal of energy in stage 2!!**
When you breathe in, you take in oxygen (a material for respiration) and when you breathe out, you release carbon dioxide and water (products of respiration)
The Respiration Equation:
C6H12O6 + 6 O2 - - - - - - - -> 6 CO2 + 6 H2O + energy
A sugar Oxygen Carbon Dioxide Water
Raw materials for respiration are sugar and oxygen. Plants and other organisms that undergo photosynthesis make their own sugar
Meanwhile, glucose in the cells of animals and other organisms comes from the food they consume
Together, photosynthesis and respiration form a cycle that keeps the levels of oxygen and carbon dioxide fairly constant in Earth’s atmosphere – living things use both gases over and over again!
Fermentation – an energy-releasing process that does NOT require oxygen!! - single-celled organisms that live where there is no oxygen, such as in the ocean or in the mud of lakes swaps, obtain energy without using oxygen!
The amount of energy released from each sugar molecule during fermentation is much lower than the amount released during respiration
Alcohol Fermentation – this occurs when yeast and other single-celled organisms break down sugars – it’s called alcohol fermentation because alcohol is one of the products; the other products are CO2 and a small amount of energy
Alcohol fermentation is important for bakers and brewers – the CO2 produced by yeast creates air pockets in bread dough, causing it to rise!
Ever run as fast as you could, in a race? What occurs?
Lactic Acid Fermentation – this takes place in your body! It occurs when your muscle cells use up the oxygen faster than it can be replaced, and since your cells lack oxygen, fermentation occurs – one product of this fermentation is acid and when it builds up, you feel a painful sensation in your muscles – your muscles feel weak and sore!