Cellular Respiration and Photosynthesis - An Introduction Earth’s energy budget Cellular energy (ATP) Mitochondria Solar energy Chloroplasts Chlorophyll Photosynthesis vs. Cellular Respiration Photosynthesis and life

Cellular Respiration

30% Reflected by Clouds or Earth’s Surface 19% Absorbed by Atmosphere and Clouds 0.023% absorbed by plants

Cell Currency (Payment) Currency = Energy = ATP We use currency (money) everyday in order to do things like buy food Cells use currency (ATP) to perform 1000’s of chemical reactions every second to keep them alive

ATP (Energy/Currency for the Cell) In order to keep the cell alive, it must perform 1000’s of reactions EVERY SECOND. Every reaction needs energy (ATP) ATP is created during cellular respiration inside the Mitochondria

Cellular Respiration The process where sugar (glucose) is converted into carbon dioxide, water and energy (ATP) The organism uses this energy to do everything Occurs in the mitochondria

Mitochondria "Powerhouse of the cell” Cells that use a lot of energy have more mitochondria (i.e. muscle cells, brain cells)

Photosynthesis

Solar Energy Solar cells convert light energy directly into electrical energy to work your TV, fan, etc. Plants do something similar. They convert light energy into chemical energy (sugar) which the organism can use to move, talk, run, etc.

Chloroplasts Chloroplasts are located inside plants They contain chlorophyll which gives plants their green color and also allows them to absorb light energy and convert it to chemical energy in the form of sugar This process is called Photosynthesis

Carbon Dioxide + Water + Light Energy  Glucose (Sugar) + Oxygen Photosynthesis Performed in the Chloroplasts of plant cells Carbon Dioxide + Water + Light Energy  Glucose (Sugar) + Oxygen

Photosynthesis + Sugar (Glucose)

Chlorophyll is a Pigment Chlorophyll is the most important pigment (color) present in plants. Other pigments are also present in the leaf. Carotenoids (orange / red) Xanthophylls (yellow / brown)

Why are plants green?

Light Light we see comes in a spectrum from purple to red Different substances absorb different colors depending on their structure Colors that the substance doesn’t absorb, it reflects. We see that reflection as the objects color

Chlorophyll Is a pigment that absorbs blue and red light but reflects green. The light is reflected into our eyes giving plants a green colour High absorption Low absorption/High reflection

How do plants use light? Chlorophyll pigments absorb blue and red regions of the spectrum. They reflect the green regions *Note* - reflecting green light also helps keep the plant cool

Carotenoids (other accessory pigments) Other accessory pigments (called carotenoids) also absorb light energy. They absorb green and reflect yellow-to-red light. This gives them a yellow-red colour

Why do some leaves turn colours in the fall? There is one other main pigment found in plants, Xanthophylls. They reflect yellow/brown light As the most abundant pigment, chlorophyll is what gives leaves their green color in spring and summer.

Why do some leaves turn colours in the fall? During winter, there is not enough light or water for photosynthesis. Therefore, the trees cut off the circulation of water, nutrients and sugar to the leaves. The green chlorophyll pigment disappears from the leaves leaving the other pigments behind. As the green fades away, we see the yellows, oranges, reds and browns. Small amounts of these colors have been in the leaves all along we just can't see them in the summer, because they are covered up by the green chlorophyll.

Photosynthesis and Cellular Respiration Notice Anything? Cellular Respiration

Photosynthesis and Cellular Respiration What is created in one reaction is used up in the other reaction!

Photosynthesis and Cellular Respiration are Connected Photosynthesis vs. Respiration video

To Photosynthesize, or not to Photosynthesize, that is the question Many organisms cannot photosynthesize (done by plants) they are called consumers Consumers – an organism that obtains its energy from consuming other organisms To obtain usable energy from food, consumers undergo cellular respiration. THEREFORE…..

Photosynthesis and Life We completely rely on the Sun! No Sun = No Photosynthesis = No Food for plants = No Food for animals = No food for larger animals No Sun = No life on Earth This is the basis behind the dinosaur extinction

Dinosaur Extinction A HUGE asteroid is thought to have hit Earth near Mexico 65 million years ago which sent up so much dust that it actually blocked the Sun for many years. No Sun = No Food = No more dinosaurs

Thinking Map Create a Venn diagram to compare and contrast Cellular Respiration with Photosynthesis.