Topic 2: Molecular biology (21 hours) 2.8 Cell respiration: Cell respiration supplies energy for the functions of life. Nature of science: Assessing the ethics of scientific research—the use of invertebrates in respirometer experiments has ethical implications. Understandings: Cell respiration is the controlled release of energy from organic compounds to produce ATP. ATP from cell respiration is immediately available as a source of energy in the cell. Anaerobic cell respiration gives a small yield of ATP from glucose. Aerobic cell respiration requires oxygen and gives a large yield of ATP from glucose. Details of the metabolic pathways of cell respiration are not needed but the substrates and final waste products should be known. Applications and skills: Application: Use of anaerobic cell respiration in yeasts to produce ethanol and carbon dioxide in baking. Application: Lactate production in humans when anaerobic respiration is used to maximize the power of muscle contractions. Skill: Analysis of results from experiments involving measurement of respiration rates in germinating seeds or invertebrates using a respirometer. Students are expected to know that an alkali is used to absorb CO2, so reductions in volume are due to oxygen use. Temperature should be kept constant to avoid volume changes due to temperature fluctuations. The ethics of the use of animals in experiments could be discussed in relation to respirometer experiments.

Topic 2: Molecular biology (21 hours) 2.9 Photosynthesis: Photosynthesis uses the energy in sunlight to produce the chemical energy needed for life. Nature of science: Experimental design—controlling relevant variables in photosynthesis experiments is essential. Understandings: Photosynthesis is the production of carbon compounds in cells using light energy. Visible light has a range of wavelengths with violet the shortest wavelength and red the longest. Visible light has wavelengths between 400 and 700 nanometres, but they are not expected to recall the wavelengths of specific colours of light. Chlorophyll absorbs red and blue light most effectively and reflects green light more than other colours. Oxygen is produced in photosynthesis from the photolysis of water. Energy is needed to produce carbohydrates and other carbon compounds from carbon dioxide. Temperature, light intensity and carbon dioxide concentration are possible limiting factors on the rate of photosynthesis. Applications and skills: Application: Changes to the Earth’s atmosphere, oceans and rock deposition due to photosynthesis. Skill: Drawing an absorption spectrum for chlorophyll and an action spectrum for photosynthesis. Skill: Design of experiments to investigate the effect of limiting factors on photosynthesis. PRACTICAL: Separation of photosynthetic pigments by chromatograph. Paper chromatography can be used to separate photosynthetic pigments but thin layer chromatography gives better results.

Biology Journal 12/11/2013 What is the chemical equation for photosynthesis? 6CO2 + 6H2O → C6H12O6 + 6O2 What happens to CO2 in photosynthesis? CO2 stays mostly intact. Hydrogen atoms are “fixed” to CO2, making glucose. What happens to H2O in photosynthesis? H2O is split, using the energy from sunlight. This is called photolysis. The H+ ions are fixed to CO2, and the O from water is given off as oxygen gas.

What do these 3 have in common? Biology Journal 10/27/2014 What do these 3 have in common?

Biology Journal 12/10/2013 The name of the pigment that plants use for photosynthesis is ______. The sunlight that plants are exposed to contains _____ of the colors of light. Chlorophyll absorbs ______ and ______ light, while it reflects ______ light, which is why plants appear to be green to us.

Photosynthesis and Cellular Respiration Whiteboard Review!

What is the chemical formula for cellular respiration? C6H12O6 + 6O2 → 6CO2 + 6H2O What is the chemical formula for photosynthesis? 6CO2 + 6H2O → C6H12O6 + 6O2

What gasses make up air? Name at least 3

The gasses that make up air (in decreasing order): Nitrogen (N2) Oxygen (O2) Argon (Ar) Carbon Dioxide (CO2) Neon (Ne) Helium (He) Methane (aka natural gas, CH4) Water Vapor (H2O)

Anaerobic Respiration Complete the below Venn diagram! Aerobic Respiration Both Anaerobic Respiration

Anaerobic Respiration Both Anaerobic Respiration Requires O2 Metabolic reactions that generate energy for the cell Happens when O2 runs out Happens in the mitochondria Initial steps are gycolysis (splitting glucose into pyruvate), which happens in cytoplasm Happens in the cytoplasm Products are CO2 and H2O Reactant is pyruvate (C3H4O3) Products are either: 1. ethanol and CO2 (yeast) 2. lactic acid (humans) High yield of ATP Low yield of ATP

Carbon dioxide and water are the reactants in photosynthesis. What happens to the carbon atoms from CO2? What happens to the oxygen atoms from CO2? What happens to the hydrogen atoms from H2O? What happens to the oxygen atoms from H2O? 6CO2 + 6H2O → C6H12O6 + 6O2 How do you think you could measure how much photosynthesis a plant is doing? Measure O2 produced, CO2 consumed, or biomass of the plant!

Apollo, god of the sun and Greek restaurants Where does the energy to build the food molecules in photosynthesis come from? The Sun Apollo, god of the sun and Greek restaurants

What is photolysis? When does this happen? Photoylsis is the breaking of H2O during photosynthesis. The O’s in water are given off as oxygen, and the H’s are fixed to CO2, to make glucose.

Sketch a graph of how light intensity effects the rate of photosynthesis.

What kind of organism does fermentation? What are the products of this? Fermentation is done by yeast. It starts with pyruvate, and creates CO2 (bubbles) and ethanol (aka alcohol)

Sketch a graph of how temperature effects photosynthetic rate.

These are the definitions for what 3 words? The diffusion of gasses (such as O2 and CO2) between the air in the lungs and the blood. Gas Exchange The controlled release of energy from organic molecules in cells to form ATP. Cellular Respiration How the muscles (diaphragm and intercostals [ribs]) move to push air into and out of the lungs. Ventilation

Complete the below Venn diagram! ATP Both ADP

Complete the below Venn diagram! ATP Both ADP Adenosine triphosphate Contain adenosine, and phosphates (2 or 3) Adenosine diphosphate High in energy Part of the energy-storage system of cells. All cells use ATP/ADP as energy source. Low energy Cells have lots of these “laying around,” ready to be used The last phosphate bond is high in energy, and can easily be formed or broken

What is the difference between chlorophyll and a chloroplast? Chlorophyll is the green-colored pigment that absorbs specific colors of light, to power photosynthesis. Chloroplast is the part of a plant cell where the chemical reaction of photosynthesis happens.

What color(s) of light do chlorophylls use?

Chlorophylls uses all the colors of the rainbow except green! Chlorophylls reflect green light, so green is not used. Mostly blue and orange light are used for photosynthesis.

Which pigment has optimal absorption only at 400 to 500 nanometers? Carotenoids! Fun fact: the name comes from carrots, because the pigment is orange in color. There’s also lots of them in apricots.

Photosynthesis (mostly) can’t happen in the winter. Why not? The sunlight is dim, and days are short CO2 + H2O → C6H12O6 + O2 Water is frozen, and thus inaccessible

Explain this science joke. Oxygen does literally grow on trees. Through photosynthesis, plants make O2, which keeps us alive. We’d better be nice to the environment!

Which of these statements are true: Write out the numbers 1 through 6. Then, write “true” or “false” for each one. Plants do photosynthesis. Plants do cellular respiration. Plants create O2. Plants remove CO2 from the air. Plants cause global warming. Plants get the energy for photosynthesis from water.

Which of these statements are true: Plants do photosynthesis. True! Plants do cellular respiration. True! Plants create O2. True! Plants remove CO2 from the air. True! Plants cause global warming. False! Plants get the energy for photosynthesis from water. False!

What reaction does this diagram outline? Fill it in!

What do these 2 have in common? A coal power plant Weightlifting

Both of these… Create CO2 Create H2O Consume O2 Burn calories Consume / release energy Break down organic (carbon-based) molecules to get energy The energy for these molecules at one point came from the sun (either food or fossil fuels)