Cell Energy:Cell Energy:

Here Comes the Sun!Here Comes the Sun!

Cell EnergyCell Energy

Why do you get Why do you get hungry? hungry?

Feeling hungry Feeling hungry is your body’s is your body’s way of telling way of telling you that your you that your cells need cells need energy!energy!

From Sun to CellFrom Sun to Cell

Plants capture energy Plants capture energy from the sun and from the sun and

change it into food change it into food through a process through a process

calledcalled

PHOTOSYNTHESIPHOTOSYNTHESISS

Food that plants Food that plants make supplies make supplies them withthem with energyenergy..

This food also This food also becomes a becomes a source of energy source of energy for organisms that for organisms that eat plants.eat plants.

PhotosynthesisPhotosynthesis::

PhotosynthesisPhotosynthesis: process by which plants, : process by which plants, algae, and some bacteria usealgae, and some bacteria use

SunlightSunlight

carbon dioxidecarbon dioxide

andand waterwater

to make foodto make food

Chlorophyll is the Chlorophyll is the main pigment main pigment used in used in photosynthesisphotosynthesis

It gives plants It gives plants their green colortheir green color

Chlorophyll is Chlorophyll is found infound in chloroplastschloroplasts..

Plants use the energy captured Plants use the energy captured by chlorophyll to changeby chlorophyll to change CARBON DIOXIDE and WATERCARBON DIOXIDE and WATER

Into Into FOODFOOD

CO2CO2 + + = =

The food is in the form of the simple The food is in the form of the simple sugar GLUCOSE, which is a sugar GLUCOSE, which is a carbohydratecarbohydrate

The energy inThe energy in glucoseglucose is used by the is used by the plant’s cellsplant’s cells

6CO6CO2 2 + 6 + 6 HH220 + light energy = C0 + light energy = C66HH1212OO66 + 6O + 6O22

Getting Energy from FoodGetting Energy from Food

AnimalAnimal cells have different ways of getting cells have different ways of getting energy from food such as:energy from food such as:

**Cellular respirationCellular respiration: uses oxygen to break : uses oxygen to break down fooddown food

**FermentationFermentation: the breakdown of food : the breakdown of food without the use of oxygenwithout the use of oxygen

Cellular RespirationCellular Respiration

Respiration meansRespiration means ““breathingbreathing””

MostMost complexcomplex organisms, from organisms, from cows to humans, cows to humans, obtains energy obtains energy through respirationthrough respiration

During cellular respiration, food (such During cellular respiration, food (such as glucose) is broken down into carbon as glucose) is broken down into carbon dioxide and water, and energy isdioxide and water, and energy is releasedreleased

Most of the energy released maintains Most of the energy released maintains body temperaturebody temperature

Some of the energy is used to formSome of the energy is used to form ATPATP (which supplies energy that fuels (which supplies energy that fuels cell activities)cell activities)

Most of the process of cellular Most of the process of cellular respiration takes place in the cellrespiration takes place in the cell membranemembrane of prokaryotic cellsof prokaryotic cells

In the cells of eukaryotes, cellular In the cells of eukaryotes, cellular respiration takes place in the respiration takes place in the mitochondriamitochondria

The equation for cellular respiration is The equation for cellular respiration is almost a complete opposite of almost a complete opposite of photosynthesis!photosynthesis!

CC66HH12120066 + 60 + 6022 -> 6CO -> 6CO22 + 6H + 6H220 + ENERGY (ATP)0 + ENERGY (ATP)

Connection Between Photosynthesis Connection Between Photosynthesis and Respirationand Respiration

Photosynthesis transforms energy from the Photosynthesis transforms energy from the sun into glucose, cells use carbon dioxide to sun into glucose, cells use carbon dioxide to make glucose, and the cells releasemake glucose, and the cells release oxygenoxygen

During cellular respiration, cells use oxygen During cellular respiration, cells use oxygen to break down glucose and release energy to break down glucose and release energy andand carbon dioxidecarbon dioxide

Each process makes the materials that are Each process makes the materials that are needed for the other process to occur needed for the other process to occur elsewhereelsewhere

FermentationFermentation

Have you Have you ever felt that ever felt that

burning burning sensation in sensation in

your leg your leg muscles muscles

when you when you run?run?

When muscle When muscle cells just can’t cells just can’t get enough get enough oxygen for oxygen for cellular cellular respiration, they respiration, they use the process use the process of fermentation of fermentation to get energyto get energy

One kind of One kind of fermentation fermentation happens in your happens in your muscles and muscles and produces lactic produces lactic acid (this is why acid (this is why you get muscle you get muscle cramps—a cramps—a buildup of acid!)buildup of acid!)

Another type of Another type of fermentation fermentation occurs in some occurs in some types oftypes of bacteriabacteria and in yeastand in yeast

In a general sense, fermentation is the conversion of a carbohydrate such as sugar into an acid or an alcohol. More specifically, fermentation can refer to the use of yeast to change sugar into alcohol or the use of bacteria to create lactic acid in certain foods. Fermentation occurs naturally in many different foods given the right conditions, and humans have intentionally made use of it for many thousands of years.

earliest uses of fermentation were most likely to create alcoholic beverages such as mead, wine, and beer.

Fermentation is a way that Fermentation is a way that cells get energy from their cells get energy from their food without usingfood without using oxygenoxygen

Yeast forms carbon Yeast forms carbon dioxide during dioxide during fermentation. The bubbles fermentation. The bubbles of carbon dioxide gas of carbon dioxide gas cause the dough to rise cause the dough to rise and leave small holes in and leave small holes in the bread after it’s baked.the bread after it’s baked.