Photosynthesis (Chapter 8) To make With light

The purpose of photosynthesis is to produce food & oxygen ATP The purpose of photosynthesis is to produce food & oxygen

Energy & Life Overview The cell process identified with energy production is photosynthesis. Plants use solar energy to convert water & carbon dioxide into high energy sugars (food) & oxygen.

Energy & Life Organisms that can make their own food from the sun are called autotrophs What does autotroph mean? Auto = self, troph = nutrition

Energy & Life Organisms that can not use the sun’s energy to make food are called heterotrophs. They obtain energy from food they eat. Herbivore - Impalas Carniovore - Leopard

Chemical Energy & ATP Cells use adenosine triphosphate, abbreviated ATP to store & release energy. ATP is used by all types of cells as their basic energy source.

ribose (a 5-carbon sugar) 3 phosphate groups ATP consists of: adenine ribose (a 5-carbon sugar) 3 phosphate groups 3 Phosphate groups Adenine Ribose ATP is used by all types of cells as their basic energy source. ATP

Adenosine Triphosphate (ATP) Adenosine Diphosphate (ADP) + Phosphate Storing Energy ADP has two phosphate groups instead of three. A cell can store small amounts of energy by adding a phosphate group to ADP. ATP ADP Energy + Energy Adenosine Triphosphate (ATP) Adenosine Diphosphate (ADP) + Phosphate Partially charged battery Fully charged battery

Releasing Energy Energy stored in ATP is released by breaking the chemical bond between the second and third phosphates. 2 Phosphate groups P ADP BLAMO!!

ATP energy is used for Lots of stuff like: active transport across cell membranes. protein synthesis. muscle contraction. ATP is the basic energy source of ALL cells!

ATP Movie 2 min video clip

Organisms that make their own food are called autotrophs. heterotrophs. decomposers. consumers.

Most autotrophs obtain their energy from chemicals in the environment. sunlight. carbon dioxide in the air. other producers.

How is energy released from ATP? A phosphate is added. An adenine is added. A phosphate is removed. A ribose is removed.

How is it possible for most cells to function with only a small amount of ATP? Cells do not require ATP for energy. ATP can be quickly regenerated from ADP and P. Cells use very small amounts of energy. ATP stores large amounts of energy.

Compared to the energy stored in a molecule of glucose, ATP stores much more energy. much less energy. about the same amount of energy. more energy sometimes and less at others.

Photosynthesis The Photosynthetic Equation: 6CO2 + 6H2O C6H12O6 + 6O2 Light Light Carbon Dioxide Water Sugars Oxygen B. Photosynthesis uses sunlight to convert water & carbon dioxide into high energy sugars (carbohydrates) & oxygen.

Light & Pigments Plants gather the sun's energy with light-absorbing molecules called pigments. The main pigment in plants is chlorophyll. There are two main types of chlorophyll: chlorophyll a chlorophyll b

special cell organelles called chloroplasts. Spirogyra sp., a filamentous green alga Light micrograph of Spirogyra sp., a filamentous green alga (Chlorophyte, Chlorophyta). Spirogyra has characteristic spiral chloroplasts (green bands) within elongated cells of a filament. The chloroplasts contain green chlorophyll pigments and are the site of photosynthesis Plant leaves are green (usually) because they contain the pigment chlorophyll in special cell organelles called chloroplasts.

What causes a rainbow?? Sunlight contains different wavelengths of light. Different wavelengths have different colors & amount of energy. Rainbows are formed by light passing through water droplets which act as prisms. Red light has the most energy and therefore passes through the prism the fastest and is bent the least. Blue light has the least energy, spends the most time in the prism and is bent the most. What causes a rainbow??

Light and Pigments (cont.) Chlorophyll absorbs light in the blue-violet and red regions of the visible spectrum. Photosynthesis requires light and chlorophyll. In the graph above, notice how chlorophyll a absorbs light mostly in the blue-violet and red regions of the visible spectrum, whereas chlorophyll b absorbs light in the blue and red regions of the visible spectrum.

Chlorophyll reflects light in the green region of the spectrum, which is why plants look green. Photosynthesis requires light and chlorophyll. In the graph above, notice how chlorophyll a absorbs light mostly in the blue-violet and red regions of the visible spectrum, whereas chlorophyll b absorbs light in the blue and red regions of the visible spectrum.

Chlorophyll absorbs light energy & the energy is transferred to electrons in the chlorophyll molecule. Raising the electrons energy. These high-energy electrons are what make photosynthesis work.

Plants use the sugars produced in photosynthesis to make oxygen. Sugars (starches, carbohydrates). carbon dioxide. protein.

The raw materials required for plants to carry out photosynthesis are carbon dioxide and oxygen. oxygen and sugars. carbon dioxide and water. oxygen and water.

The principal pigment in plants is chloroplast. chlorophyll. carotene. carbohydrate.

The colors of light that are absorbed by chlorophylls are green and yellow. green, blue, and violet. blue, violet, and red. red and yellow.

Photosynthesis Reactions The chloroplast Photosynthesis takes place inside the chloroplasts of plants & algae.

Chloroplasts of plants & algae.

Chloroplasts contain thylakoids—saclike photosynthetic membranes. Single thylakoid Stroma Chloroplast

Thylakoid membrane organize chlorophyll into clusters called photosystems, which collect light. Chloroplast

Photosynthetic reactions There are two types of photosynthesis reactions: Light-dependent reactions take place in the thylakoid membranes. Calvin cycle (Light-independent) reactions takes place in the stroma (outside the thylakoid membranes).

Light-Dependent Reactions

Light- dependent reactions H2O CO2 Light NADP+ ADP + P Light- dependent reactions Calvin Cycle Calvin cycle The process of photosynthesis includes the light-dependent reactions as well as the Calvin cycle. Chloroplast O2 Sugars

Light-Dependent Reactions (fig 8-10) Produce: Oxygen, ATP, & NADPH (electron carrier). ATP synthase + O2 2H2O The light-dependent reactions use energy from sunlight to produce ATP, NADPH, and oxygen. ADP 2 NADP+ 2 2 NADPH

Light-dependent steps Reactions occur in the thylakoid membranes of chloroplasts Light is absorbed by chlorophyll molecules in the thylakoid membrane. Thylakoid membrane Stroma Chloroplast

Light-dependent Steps (Fig 8-10) Water is broken down into hydrogen ions oxygen atoms – we breath energized electrons Inner Thylakoid space e- carriers + O2 2H2O Thylakoid Memebrane Stroma Chlorophyll

Light-dependent Steps Electrons move through the electron transport chain & carry H+ ions from the stroma into the inner thylakoid space. Inner Thylakoid space e- carriers Thylakoid Memebrane ADP Stroma

Light-dependent Steps NADP+ then picks up these high-energy electrons, along with H+ ions, and becomes NADPH. + O2 2H2O The light-dependent reactions use energy from sunlight to produce ATP, NADPH, and oxygen. 2 NADP+ 2 2 NADPH

Light-dependent Steps Hydrogen ions pass through ATP synthase & convert ADP into ATP. Inner Thylakoid space Thylakoid Memebrane Stroma ADP

Light-Dependent Products The light-dependent reactions use sunlight, H2O, & CO2 to produce: Oxygen Change ADP into ATP Change NADP+ into high-energy electron carrier NADPH.

Calvin Cycle (light-independent reaction) The Calvin cycle takes place in the stroma of chloroplasts & does not require light. The Calvin cycle uses CO2 + ATP & NADPH (created in light-dependant reactions) to produce sugars.

Light- dependent reactions Inside a Chloroplast H2O CO2 Light NADP+ ADP + P Light- dependent reactions Calvin Cycle Calvin cycle The process of photosynthesis includes the light-dependent reactions as well as the Calvin cycle. Chloroplast O2 Sugars

Calvin Cycle (light-independent reaction) Key Steps: 6 CO2 molecules from atmosphere combine with 6 -5 carbon molecules know as RuBP. Product splits into 2 -3carbon molecules. Energy from ATP & NADPH convert three carbon molecules into higher energy forms known as G3P. Every 6 cycles produces 2 three carbon molecules which are used to create sugars, lipids, other compounds.

5-Carbon Molecules Regenerated Sugars and other compounds Calvin Cycle fig. 8-11 12 12 ADP 6 ADP 12 NADPH 6 12 NADP+ 5-Carbon Molecules Regenerated Sugars and other compounds

Photosynthesis 1 Min 30 sec video clip

Photosynthesis Concept Map Section 8-3 Photosynthesis includes Light- dependent reactions Calvin cycle takes place in uses use take place in Energy from sunlight Thylakoid membranes Stroma NADPH ATP to produce of to produce High-energy sugars ATP NADPH O2 Chloroplasts

What are the products of photosynthesis? ATP What are the products of photosynthesis?

What are the raw materials of photosynthesis? ATP What are the raw materials of photosynthesis?

What is the energy source of photosynthesis? ATP What is the energy source of photosynthesis?

In plants, photosynthesis takes place inside the thylakoids. chloroplasts. photosystems. chlorophyll.

Energy to make ATP in the chloroplast comes most directly from hydrogen ions flowing through an enzyme in the thylakoid membrane. transfer of a phosphate from ADP. electrons moving through the electron transport chain. electrons transferred directly from NADPH.

NADPH is produced in light-dependent reactions and carries energy in the form of ATP. high-energy electrons. low-energy electrons. ADP.

What is another name for the Calvin cycle? light-dependent reactions light-independent reactions electron transport chain photosynthesis