Photosynthesis and Cell Respiration A beginners guide Why

Photosynthesis and Cell Respiration A beginner’s guide…

Why are we learning this? • Standard we have to master: • SB 3 a: – Explain the cycling of energy through the processes of photosynthesis and respiration.

Hmmm… • What is an autotroph? – Any organism that can produce its own sugar inside its cells. – Example: Plants, some protists and some bacteria • What is a heterotroph? – Any organism that needs to eat to get its sugar – Examples: animals, fungi, some protists

ATP • What is ATP? – It is the energy molecule for cells. • What does ATP stand for? – Adenosine Tri-Phosphate • What is it made of? – Adenine – Ribose – 3 phosphates

Wait just a dern minute!!! • Adenine + ribose + phosphate? – That sounds familiar…. – Hmmm…. . – OH! • It’s a nucleotide! – Wait…. so ATP is a nucleic acid? • No…it’s a nucleotide (monomer), but it is not chained together to be a nucleic acid (polymer).

• Is ATP a Nucleic Acid? – No. • Why? – It is just one nucleotide. – To be a nucleic acid, there has to be more than one nucleotide in a chain.

DRAW THE NEXT SLIDE IN YOUR IAN • Label it the ATP CYCLE

ATP Cycle • Copy onto your notes:

Hmmmm? ? ? . . . Questions to consider… • Why are plants green? – Because of the chlorophyll in the chloroplasts. • What does chlorophyll do? – It absorbs light. • Which wavelength (color) of light is not absorbed by chlorophyll? – Green – That’s why plants appear green…. They REFLECT green light and you SEE the green light that is reflected.

Why are plants green?

Plant Cell Remember • Plant cells are Eukaryotic • Chloroplasts are membrane bound Organelles • Chloroplasts have a double membrane • Chloroplasts are found in PLANTS, Algae, and some protists

Actual plant cells

The membranes are IMPORTANT!!

Protists • unicellular "animal-like" protozoa, the "plant-like" protophyta (mostly unicellular algae), and the "fungus-like" slime molds and water molds. • https: //youtu. be/GScyw 3 ammmk

Chloroplasts • 3 main parts: • Thylakoid: – A disk-shaped structure in the chloroplast where specific reactions take place. – Looks like a quarter or a dime • Granum: – A stack of thylakoids – Plural = grana – Looks like a stack of quarters or dimes • Stroma – The cytoplasm inside the chloroplast

Granum

Grana

Photosynthesis • Is the process by which plants make sugars needed for energy production. • Requirements (aka: Reactants): – Carbon Dioxide (CO 2) – Water (H 20) – Light

Hmmm… • Where do plants get sunlight from? – The sun. • Where do plants get Carbon Dioxide from? – The atmosphere. • Where do plants get water from? – The ground

Photosynthesis • Equation: 6 CO 2 + 6 H 2 O + light C 6 H 12 O 6 + 6 O 2 What is C 6 H 12 O 6 ? A sugar called Glucose What are the “reactants”? What are the “products”? CO 2, H 20, & LIGHT C 6 H 12 O 6 & O 2

IAN WORK • GRAB A SHEET FROM THE BACK BASKET AND FOLLOW THE INSTRUCTIONS • YOU have 10 Minutes • YOU ONLY NEED TO LABEL THE OUTSIDE PICTURE • We will do the INSIDE TOGETHER

• 2 parts (reactions) of photosynthesis: – 1. ) Light Dependent Reactions • Need light to occur. • Occurs in the thylakoids. • Produces oxygen (waste), ATP and NADPH – NADPH is an electron carrier – ATP is a storage molecule for energy – Oxygen is…well, oxygen

• 2. ) Light Independent Reactions • • AKA: ; the Calvin Cycle Occur in the Stroma. Can occur with or without light. Produces glucose (C 6 H 12 O 6) = FOOD

Factors effecting photosynthesis • These things can either speed up or slow down the rate of photosynthesis: • 1. ) Amount of light • 2. ) Amount of water • 3. ) Temperature

Question #1 • Where in the plant does Photosynthesis take place? • • A. ) in the nucleus B. ) in the cytoplasm C. ) in the chloroplast D. ) in the ribosome

Question #2 • Which of the following is NOT a reactant for photosynthesis? • • A. ) water B. ) sugar C. ) carbon dioxide D. ) light

#3 • Which of the following is the correct equation for photosynthesis? • A. ) 6 CO 2 + light C 6 H 12 O 6 + 6 H 20 + 6 O 2 • B. ) 6 CO 2 + 6 H 20 + light C 6 H 12 O 6 + 6 O 2 C. ) C 6 H 12 O 6 + 6 O 2 6 CO 2 + 6 H 20 + light D. ) C 6 H 12 O 6 + 6 H 20 + 6 O 2 6 CO 2 + light

#4 • Which of the following occurs in the light reactions? • A. ) CO 2 is produced. • B. ) Oxygen is produced • C. ) sugar is produced • D. ) Light is produced.

#5 • The dark reactions: • A. ) can only occur in the dark. • B. ) can occur whethere is light or not. • C. ) produce oxygen • D. ) Produce ATP

Assignment – Homework if you do not finish. • Grab a piece of Copy Paper and create mini- poster of photosynthesis. • You will need to show the formula • You will need to have a drawing • You will need to show (using arrows) all products and reactants • You will need to add color.

Draw graph from p. 116 here.

Cell Respiration Fun for all eukaryotic organisms….

Cellular respiration • Cellular respiration is what cells do to break up sugars into a form that the cell can use as energy. This happens in all forms of life. Cellular respiration takes in food and uses it to create ATP, a chemical which the cell uses for energy

Background • Cell respiration (C. R. ) occurs in the cytoplasm and the mitochondria. • It occurs in ALL eukaryotic cells. • The purpose: – use glucose to make 36 ATP molecules.

Equation • C 6 H 1206 + 6 O 2 6 CO 2 + 6 H 20 + 36 ATP • Hmmmm…does this look familiar? • What are the reactants? – Glucose and oxygen • What are the products? – Carbon dioxide, water, and ATP

• There are 3 major parts to cell respiration: 1. ) Glycolysis 2. ) The Krebs cycle 3. ) The electron transport chain

Let’s talk about glycolysis: • Where does it occur? – In the cytoplasm of the cell • Does it need oxygen? – No! This part of C. R. is “anaerobic” • An- = without • -aerobic = oxygen • What happens? – Glucose is broken in half to create 2 “pyruvic acid” molecules. – 4 ATP are produced, but 2 are used in the process of glycolysis, leaving a net gain of 2 ATP.

Let’s talk about the next step…the Krebs Cycle • AKA: the citric acid cycle • Where does it occur? – In the mitochondria • Does it require oxygen? – YES!!! • What happens? – The pyruvic acids (produced in glycolysis) are changed into citric acid. – Result: 2 ATP are produced.

Come on ride that chain…. ride it! Whoot Whooo!!! • The Electron Transport Chain! – Where does it occur? • In the mitochondria – Does it need oxygen? • YES!!! – What happens? • In glycolysis and the Krebs cycle, high energy electrons were produced. • These electrons are used to make 32 ATP

Summary Step Glycolysis Krebs Cycle Electron Transport Chain Where does it occur Does it use Oxygen? How many ATP produced (net) cytoplasm No 2 Mitochondria Yes 2 Yes 32 Mitochondria

What happens if there is a lack of Oxygen ?

What happens if there is a lack of oxygen? • Then “Lactic Acid Fermentation” occurs. – After glycolysis, if there is a lack of O 2 (perhaps due to increased exercise), the pyruvic acid cannot enter the Krebs Cycle. – Instead, the pyruvic acids are changed into lactic acid, which when used by your cells gives 2 ATP. – Problem: lactic acid is poison for the cells, which you feel as “burning” when you exercise. – You cannot continue for long with this burning, so typically, you slow down and breathe more to get oxygen.

Another fermentation…not in your cells. • Alcohol Fermentation: – Occurs in yeast when making bread and beer. – Yeast produces alcohol as a waste product when there is low oxygen levels. • Yes, THAT kind of alcohol. – THIS DOES NOT HAPPEN IN YOUR CELLS! • If it did, people would exercise to get drunk. All of our students who skip class would be at the track running laps!

Let’s review: Comparison Photosynthesis Cell Respiration Function: Glucose production Location: Chloroplasts Energy (ATP) Production Cytoplasm and Mitochondria Equation: You write it down. Once again…you do it. Reactants: CO 2; H 20; light Glucose & O 2 Products: Glucose & O 2 CO 2; H 20; 36 ATP All Eukaryotes! What type of organisms do this? Autotrophs, such as plants. (so…NO BACTERIA!)