Cell Energetics The cell’s energy compound is ATP. All cells (from bacteria, to plants, to humans) use ATP for cell energy. ATP video clip

Where to we get the energy to convert ADP to ATP??? FOOD! Cellular respiration uses food to convert ADP to more ATP.

Cellular Respiration The process by which cells break down food molecules (glucose) to produce energy (ATP molecules). ATP is cell energy for growth, movement, active transport, etc Occurs in the mitochondria Aerobic cellular respiration needs oxygen and glucose to begin.

Chemical Equation for Respiration: C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + ATP Glucose + 6 oxygen  6 carbon dioxide + 6 water +ATP

3 Steps of Cellular Respiration 1. Glycolysis –Glucose is split in half, producing 2 pyruvic acids. –Produces 2 pyruvic acids, 2 net ATP and 2 NADH (electron carrier) to be used in the 3 rd step. –Location = cytoplasm

Invests 2 ATP Produces 4, so there is a net gain of 2 ATP. Produces NADH, which will be used in the 3 rd step

2. Krebs Cycle (Citric Acid Cycle) –Pyruvic acids from glycolysis are broken down into carbon dioxide –Produces 2 ATP, CO 2, NADH, and FADH 2 (reminder, NADH and FADH 2 are electron carriers) –Location = mitochondria

More NADH and another carrier FADH2 are produced to use for the last step.

3. Electron Transport Chain –Uses NADH and FADH 2 to convert ADP in ATP. –NADH and FADH 2 provide the electrons. –Oxygen is needed to catch electrons at the end of the chain –Produces ATP. –Look at diagram on page 229. –Total ATP produced from one molecule of glucose = ATP

Cellular Respiration

Where do we get the food? You need a food molecule and oxygen to begin the three steps of cellular respiration. Animals get the food from consuming it. Plants get food by the process of photosynthesis.

PHOTOSYNTHESIS

PHOTOSYNTHESIS: The process by which autotrophs (plants/algae) convert sunlight into chemical energy (food).

Autotroph An organism that makes its own food. Also called producer.

Leaves contain an important pigment called chlorophyll. Pigments are molecules that absorb and reflect light.

*Chlorophyll absorbs red, blue and violet light and reflects the color green.

*Chlorophyll is located in an organelle called chloroplast. *Chloroplasts carry out the process of photosynthesis

Structures inside a chloroplast : Thylakoid: Single disks that absorb light energy (have chlorophyll) Grana: Stacks of thylakoids Stroma: gel-like fluid that is inside chloroplasts

Thylakoid Stroma Grana Chloroplast

Chemical Equation for Photosynthesis 6 CO H 2 O 6 O2 O2 + C 6 H 12 O 6 sunlight 6 carbon dioxide + 6 waters= 6 oxygen + 1 glucose

2 cycles for Photosynthesis: 1. Light-dependent reaction: requires sunlight, water, NADP, and ADP and produces oxygen, NADPH, and ATP. Occur in the thylakoid membranes.

Light reactions, similar to Electron transport chain of respiration

Video clip of the light reactions Light-dependent reaction video clip from youtubeLight-dependent reaction video clip from youtube

2. Calvin Cycle (light- independent/dark reaction): uses CO 2, ATP, and NADPH; produces sugar (glucose), ADP, and NADP Occurs in the stroma of the chloroplast

Calvin cycle video clip Calvin cycle youtube video clip

Compare the equations Photosynthesis: 6 CO H 2 O  6 O 2 + C 6 H 12 O 6 Respiration: C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O + ATP

Photosynthesis Song Photosynthesis, in the chloroplasts Reactants are, Reactants are: Carbon dioxide, water, energy from sunlight, Chlorophyll, that's what you need!

Photosynthesis, in the chloroplasts Products are, Products are: Oxygen released, energy stored in glucose, That’s what you make! That’s what you make!

Photosynthesis Game Goal: 1. Acquire all four ingredient cards Chloroplasts, Light, Carbon Dioxide, and Water 2. Acquire the two product cards: Sugar and Oxygen 3. Use the delay cards like “out of gas, desert, night time, dead leaves” to hinder your opponents (Slow them down from photosynthesizing and winning the game!)