Cells and Energy Photosynthesis & Cellular Respiration Cells Lecture III

Biology Standards Covered 1f ~ students know usable energy is captured from sunlight by chloroplasts and is stored from the synthesis of sugar from carbon dioxide 1f ~ students know usable energy is captured from sunlight by chloroplasts and is stored from the synthesis of sugar from carbon dioxide 1g ~ students know the role of the mitochondria in making stored chemical-bond energy available to cells by completing the breakdown of glucose to carbon dioxide 1g ~ students know the role of the mitochondria in making stored chemical-bond energy available to cells by completing the breakdown of glucose to carbon dioxide *1i ~ students know how chemiosmotic gradients in the mitochondria and chloroplasts store energy for ATP production *1i ~ students know how chemiosmotic gradients in the mitochondria and chloroplasts store energy for ATP production

Photosynthesis There are only two types of organisms on this planet There are only two types of organisms on this planet Producers – living things that make their own food as well as food for other living things Producers – living things that make their own food as well as food for other living things Consumers – living things that rely upon consuming another organism for food (energy) Consumers – living things that rely upon consuming another organism for food (energy) What are you? What are you?

Photosynthesis Producers Producers An example of a producer would be a plant and how it “makes” food could be through a process known as photosynthesis An example of a producer would be a plant and how it “makes” food could be through a process known as photosynthesis This takes place in the chloroplast organelle inside of a plant cell This takes place in the chloroplast organelle inside of a plant cell

Photosynthesis Photosynthesis – is the process of using energy from the sun to convert CO 2 and H 2 O into chemical energy in the form of sugars Photosynthesis – is the process of using energy from the sun to convert CO 2 and H 2 O into chemical energy in the form of sugars Sunlight radiates the Earth as visible light that we see and is made up of many different colors (ROYGBIV) Sunlight radiates the Earth as visible light that we see and is made up of many different colors (ROYGBIV) Red, Orange, Yellow, Green, Blue, Indigo, and Violet Red, Orange, Yellow, Green, Blue, Indigo, and Violet

Photosynthesis Chlorophyll is a molecule in plants that absorbs visible light from the sun Chlorophyll is a molecule in plants that absorbs visible light from the sun There are two types (Chlorophyll a and Chlorophyll b ) There are two types (Chlorophyll a and Chlorophyll b ) Together they absorb mostly red and blue wavelengths of light while “reflecting” some yellow and much of the green Together they absorb mostly red and blue wavelengths of light while “reflecting” some yellow and much of the green This is why you see plant leaves as “green” because of the ‘reflected’ color This is why you see plant leaves as “green” because of the ‘reflected’ color

Photosynthesis Inside of the chloroplast are two structures important to photosynthesis Inside of the chloroplast are two structures important to photosynthesis Grana – are stacks of membranes that look like a stack of pennies surrounded by compartments called thylakoids Grana – are stacks of membranes that look like a stack of pennies surrounded by compartments called thylakoids Stroma – is the fluid surrounding the grana inside of the chloroplast Stroma – is the fluid surrounding the grana inside of the chloroplast

Photosynthesis There are two stages to Photosynthesis There are two stages to Photosynthesis Light-dependent reactions (First) Light-dependent reactions (First) Chlorophyll absorbs energy from sunlight and energy is transferred along thylakoids, Water is broken down and Oxygen is produced Chlorophyll absorbs energy from sunlight and energy is transferred along thylakoids, Water is broken down and Oxygen is produced Energy that is carried along thylakoids is transferred in molecules of ATP Energy that is carried along thylakoids is transferred in molecules of ATP Light-independent reactions (Second) Light-independent reactions (Second) Carbon Dioxide is added to a cycle of chemical reactions building larger molecules of sugars Carbon Dioxide is added to a cycle of chemical reactions building larger molecules of sugars Energy, ATP, from the light-dependent reaction is used to form these simple sugars Energy, ATP, from the light-dependent reaction is used to form these simple sugars

Photosynthesis in a Chloroplast C 6 H 12 O 6 is Glucose, a simple sugar that feeds all living things CO 2 (gas) is used to make the sugar Glucose

Photosynthesis in Chloroplasts

Cellular Respiration The mitochondrion and its role in providing plants and animals with energy

Chemical Energy for Organisms ATP – Adenosine triphosphate ATP – Adenosine triphosphate An energy rich molecule that provides all living things with energy for growth, repair, and maintenance An energy rich molecule that provides all living things with energy for growth, repair, and maintenance ADP – Adenosine diphosphate ADP – Adenosine diphosphate Energy comes from the release of the 3 rd phosphate of ATP Energy comes from the release of the 3 rd phosphate of ATP This creates ADP This creates ADP

What is ATP? ATP is molecule that acts like a chemical form of electricity for all living things! ATP is molecule that acts like a chemical form of electricity for all living things! Without ATP, you could not move, think, breathe, or grow! Without ATP, you could not move, think, breathe, or grow!

What is Cellular Respiration? Cellular respiration is when chemical energy is released from sugars and other carbon based molecules to make ATP ~ when oxygen is present Cellular respiration is when chemical energy is released from sugars and other carbon based molecules to make ATP ~ when oxygen is present This means that cellular respiration is aerobic in that it needs oxygen to take place This means that cellular respiration is aerobic in that it needs oxygen to take place

Energy Production’s 2 Stages Glycolysis & Cellular Respiration

How does it work? Cellular Respiration (stage 2) takes place in a mitochondrion Cellular Respiration (stage 2) takes place in a mitochondrion Some cells have several Some cells have several IMPORTANT! ~ Before cellular respiration can take place ~ IMPORTANT! ~ Before cellular respiration can take place ~ Food molecules MUST be broken down into simpler molecules Food molecules MUST be broken down into simpler molecules The break down of glucose into (2) 3~Carbon Sugars is called Glycolysis The break down of glucose into (2) 3~Carbon Sugars is called Glycolysis Glycolysis occurs in the cytoplasm Glycolysis occurs in the cytoplasm

Glycolysis Glucose 2 Pyruvic acid To the electron transport chain This happens in the cytoplasm * Glycolysis is anaerobic because it does NOT require oxygen to take place! This happens in the cytoplasm 2 ATP are used to “start” Glycolysis and 4 ATP are made in the second stage. That means Glycolysis yields a “net” of +2 ATP

Cellular Respiration happens in the Mitochondrion 2 Pyruvate molecules from glycolysis go into Stage 1

The Kreb’s Cycle aka. Citric Acid Cycle STAGE 1: The Krebs Cycle STAGE 1: The Krebs Cycle During stage 1 the (2) 3~Carbon pyruvate molecules from Glycolysis enter the mitochondria During stage 1 the (2) 3~Carbon pyruvate molecules from Glycolysis enter the mitochondria These molecules undergo a series of chemical reactions and a small amount of ATP is produced (2 ATP Molecules) These molecules undergo a series of chemical reactions and a small amount of ATP is produced (2 ATP Molecules) The waste product of the Kreb’s Cycle is 6 CO 2 (Carbon dioxide) molecules The waste product of the Kreb’s Cycle is 6 CO 2 (Carbon dioxide) molecules Energy is transferred to “power” Stage 2 of Cellular Respiration Energy is transferred to “power” Stage 2 of Cellular Respiration

Kreb’s Cycle NADH FADH 2 Electron Transfer Phosphorylation The Kreb’s Cycle generates NADH and FADH 2 that are fed into stage 2 ~ Electron Transfer Phosphorylation

Stage 2 of Cellular Respiration Stage 2: Electron Transfer Phosphorylation Stage 2: Electron Transfer Phosphorylation Energy from Glycolysis and the Krebs Cycle enter Stage 2 to “power” the reactions Energy from Glycolysis and the Krebs Cycle enter Stage 2 to “power” the reactions NADH and FADH 2 are “spent” to create a H+ ion gradient inside of a mitochondrion NADH and FADH 2 are “spent” to create a H+ ion gradient inside of a mitochondrion When these protons, H+ ions, “rush back in” to the mitochondrion, it generates ATP! When these protons, H+ ions, “rush back in” to the mitochondrion, it generates ATP! Stage 2 makes 32 ATP molecules! Stage 2 makes 32 ATP molecules! Glycolysis and the Kreb’s Cycle each only made 2 Glycolysis and the Kreb’s Cycle each only made 2

Cellular Respiration & Glycolysis

H+ Proton Gradient Formation The inner and outer compartments of the mitochondrion are where the H+ ions are “pumped” and allowed back in for ATP generation

H+ Proton Gradient Formation

ATP Generation through ATP Synthase