Heterotroph - Obtain energy by consuming other organisms
Consumers are heterotrophs (ex: animals)
Autotroph - Use energy from the sun to make their own food.
Producers are autotrophs (ex: plants)
Autotrophs convert energy from the sun into chemical energy in glucose.
Photosynthesis
Photosynthesis = the process by which plants convert the energy of the sun into sugar
Where does photosynthesis take place?
●Takes place mainly in plants.
●Where in plants? Mainly in the leaves.
●Where in the leaves? In the chloroplasts.
Chloroplasts are the organelles found in plant cells (and only in plant cells) where chlorophyll absorbs energy from the sun and photosynthesis takes place.
●Chlorophyllare pigment molecules that absorb sunlight.
●Chlorophyll absorbs a lot of the red and blue light but reflects green light.
●Reflection of the green light is what makes chloroplasts green, and thus makes leaves green.
Reactants of photosynthesis (these are the inputs):
●Water - Absorbed by roots in the soil and taken to the leaves by the stem
●Carbon Dioxide - Comes from the air and enters the leaves through small holes
●Sunlight - light from the sun provides the energy
Products of photosynthesis (these are the outputs)
●Glucose - The sugar that stores the energy from the sun as chemical energy.
- Can be used right away as an energy source(Respiration)
- Can be stored as starch
- Can be used for GROWTH - This is where the mass of a plant comes from.
●Oxygen - Released from the leaves through small holes.
Balanced Chemical Equation:
Main idea: Photosynthesis uses energy from the sun to make glucose. The energy from the sun is stored as chemical energy in the glucose. This process occurs in the chloroplasts found in plant cells.
Where does the mass of a plant come from?
●The carbon from carbon dioxide is converted to the carbon of glucose during photosynthesis, which can then be used for growth to make the leaves, stems, roots, fruits, etc. So all of that stuff (mass) is coming from the carbon dioxide.
Factors affecting the rate of photosynthesis (see graphs on pg. 124)
●Temperature - Photosynthesis occurs at its highest rate at an optimal temperature. Above and below that optimal temperature the rate of photosynthesis will decrease.
●Carbon dioxide levels - The more carbon dioxide the faster the rate of photosynthesis (eventually reaches a maximum where it stays constant)
●Light Intensity - The more intense sunlight the faster the rate of photosynthesis (eventually reaches a maximum where it stays constant)
Cellular Respiration
Where does cellular respiration take place?
●Takes place in both animals AND plants
●Takes place in the mitochondria of animal and plant cells.
What is the purpose of cellular Respiration?
●To convert the chemical energy stored in glucose into ATP
●ATP is used as an energy source in the cells.
What are the reactants of cellular respiration?
●Glucose
○Animals get glucose by consuming other organisms
○Plants make their own glucose (through photosynthesis)
●Oxygen - comes from the air, animals breathe it in
What are the products of cellular respiration?
●ATP - Used as an energy source in cells
●Carbon Dioxide - Breathe Out
●Water - Sweat, Urine, etc.
Balanced Chemical Equation:
Main Idea: Cellular Respiration breaks down glucose and converts the chemical energy stored in glucose to ATP, which can be used as an energy source for cells. This process occurs in the mitochondria found in both animal and plant cells.
Energy
●All energy comes from the sun.
●Photosynthesis converts the energy from sun into chemical energy in glucose.
●Respiration then converts the chemical energy in glucose into ATP which provides energy for all the cells.
Matter
●All matter is conserved.
●The products of photosynthesis (glucose and oxygen) become the reactants for cellular respiration. Then the products of cellular respiration (carbon dioxide and water) become the reactants for photosynthesis.
●We are cycling matter in order to transfer the energy from the sun to the energy in ATP, which cells are able to use.
●This is why we say photosynthesis and cellular respiration are complementary reactions