Energy for Life: Photosynthesis and Cellular Respiration

Energy for Life: Photosynthesis and Cellular Respiration

Energy All living things need energy in order to perform life processes. Life processes include: heart beating, moving, making molecules, etc. We run on chemical energy Energy can not be recycled, so organisms constantly need to get/make energy.

Ways to Get Energy Autotrophs- Make their own energy through photosynthesis Autotrophs are also called producers because they can make their own food They are the start of the food chain

Ways to Get Energy Heterotrophs- Get energy by eating other organisms. Heterotrophs are also called consumers because they consume other animals.

Consumers/Heterotrophs Herbivores Carnivores Omnivores Scavengers Decomposers Detritivores

Consumer: Herbivores Obtain energy and nutrients by eating plant leaves, roots, seeds, or fruits. Examples? cows, caterpillars, and deer.

Consumer: Carnivores Kill and eat other animals. Catching and killing prey can be difficult and requires energy, but meat is generally rich in nutrients and energy and is easy to digest. Examples? snakes, dogs, cats, otters

Consumer: Omnivores Animals whose diets naturally include a variety of different foods that usually include both plants and animals. Examples? Humans, bears, pigs

Consumer: Scavengers Animals that consume the carcasses of other animals that have been killed by predators or have died of other causes. Examples? vulture

Consumer: Decomposers Such as bacteria and fungi, feed by chemically breaking down organic matter. The decay is part of the process that produces detritus. Examples? mushrooms

Detritus Small pieces of dead and decaying plant and animal remains.

Consumer: Detritivores Feed on detritus particles, often chewing or grinding them into even smaller pieces. They commonly digest decomposers that live on, and in, detritus particles. Examples? many types of mites, snails, shrimp, & crabs

Autotrophs and Heterotrophs in the Food Chain What would happen to heterotrophs (consumers) if all of the autotrophs (producers) died?

What do Organisms Use for Energy? Organisms can use two different types of energy: Glucose (sugar, C6H12O6) ATP

Why Both? Glucose Has more energy than ATP, but it can have too much energy for the cell to use Good for storing and transporting energy ATP Contains the right amount of energy for the cell to use Not as stable (does not store energy for very long)

Types of Energy Glucose: Stores energy as food ATP: Usable energy Glucose can be converted into ATP Glucose (sugar)- stores energy as food

Making and Using Energy PhotosynthesisConverts sunlight energy into glucose (sugar) Cellular RespirationBreaks down glucose into ATP (usable energy) The two processes work together to store and release energy in plants

Photosynthesis Only in plant cells Converts light energy into chemical energy (glucose) Releases oxygen as a waste product 6CO2 + 6H2O + Light Energy C6H12O6 + 6O2 TedEd- Photosynthesis

Photosynthesis- Location Occurs in the chloroplasts of plant cells Stroma- liquid inside the chloroplast; dark reactions take place here Thylakoid- light reactions take place here Granum- a stack of thylakoids

Photosynthesis- About Chlorophyll Chlorophyll is a type of pigment Molecules that absorb certain wavelengths of light and reflects/transmits others Chlorophyll reflects green light, and therefore makes the plant look green

Photosynthesis- Other Types of Pigments Accessory Pigments: 1. Carotenoids = orange 2. Tannins = brown 3. Anthocyanins = pink & purple

Necessary Conditions For Photosynthesis: 1. Light 2. Chlorophyll 3. Carbon dioxide (CO2) 4. Water (H2O)

Photosynthesis

Photosynthesis There are two steps to photosynthesis: 1. Light Reactions- light is used to split water (H2O) into H2 and O 2. Dark Reactions- Hydrogen (H2) and Carbon dioxide (CO2) are used to make glucose (C6H12O6) Break Down of Photosynthesis DE- Photosynthesis

Photosynthesis Overview Start: End: Carbon dioxide Water Light Oxygen Glucose (sugar)

What about plants that don t get sunlight? Chemosynthesis: Instead of photosynthesis, plants can take chemical energy (instead of light energy) and convert it into sugars. Some bacteria; organisms on the seafloor

Cellular Respiration In plant and animal cells Breaks down glucose and releases chemical energy in the form of ATP Releases carbon dioxide as a waste product C6H12O6 + 6O2 6CO2 + 6H2O + ATP

Cellular Respiration Occurs in mitochondria

Cellular Respiration There are three steps: 1. Glycolysis 2. Krebs cycle 3. Electron transport Each of these steps is involved in converting glucose (food) to ATP (energy) Break Down of Cellular Respiration

Cellular Respiration Overview Start: End: Glucose (sugar) Oxygen Carbon dioxide Water ATP

Anaerobic Respiration Making ATP without oxygen Also called fermentation

Anaerobic Respiration/Fermentation There are two types of fermentation: Lactic acid Alcohol fermentation

Lactic Acid Fermentation Completes the first part of cellular respiration (glycolysis) Does not use oxygen Produces energy and lactic acid Muscle cells use lactic acid fermentation for energy Why would this happen?

Lactic Acid Fermentation A buildup of lactic acid makes muscles score Warm down Stretch Drink plenty of fluids

Alcohol Fermentation Yeast is used Completes the first part of cellular respiration (glycolysis) Does not use oxygen Produces ethanol and carbon dioxide Used to make: Bread Wine Biofuel (ethanol)

Why is Anaerobic Respiration/Fermentation Important? Organisms can live where there s little or no oxygen Deep water Soil Digestive tracts of organisms It makes ATP quickly

Discovery Education Video Elements of Biology: Matter and Energy: Organization in Living Systems (20 min)