Biology Concept 4

Chlorophyll

A green pigment that captures light energy for photosynthesis.

Photorespiration

A metabolic pathway that consumes oxygen, releases carbon dioxide, generates no ATP, and decreases photosynthetic output; generally occurs on hot, dry, bright days, when stomata close and the oxygen concentration in the leaf exceeds that of carbon dioxide.

Chemosythesis

A process of an organism making its own food using chemicals instead of sunlight like in photosynthesis.

Summarize where all energy on earth comes from and the overall process it goes through to be in a usable form of ATP for consumers like us

All of the energy on Earth comes from sunlight all organisms on Earth need this energy to survive. The process it has to go through to be in a usable form of ATP for consumers like us is Photosynthesis. The overall process is by which sunlight chemically converts water and carbon dioxide into chemical energy that is then stored as glucose.

Stroma

Fluid portion of the chloroplast; outside of the Thylakoids

Photosystems

Light-collecting units of the chloroplast.

Describe three factors that affect the rate of photosynthesis

One factor is light intensity. If there is more light, the reactions will happen faster. The second factor is the amount of CO2 available. The more CO2, the faster the reactions. This is only true when there is not too much for the plant to be able to absorb it. The third factor is temperature. The higher the temperature, the faster the reactions. This is limited, because if it is too warm then enzymes could melt or become denatured.

Explain the alternate pathways some plants, like cacti and corn, will take to access energy

One type is CAM, done by cacti. They open the stomata at night and close them during the day. This is opposite to normal plants. They do this because it is too warm for the stomata to be open during the day where they are. The second type is C4. This is done by corn. They partially close their stomata only during the hottest part of the day. This is possible because they only need half as much water as normal plants.

Photosynthesis

Photosynthesis is a process used by plants and other organisms to convert light energy, normally from the Sun, into chemical energy that can be later released to fuel the organisms' activities. Photosynthesis can be represented through this equation: 6CO2 + 6H2O → C6H12O6 + 6O2.

Explain why plants are green

Plants have chloroplasts in their cells filled with chlorophyll, a pigment that absorbs every color of sunlight except for green, and that means green is reflected.

Electron Carriers

Proteins are arranged in chains on the membrane to allow the transfer of electrons from one carrier to another.

Stomata

Small openings on the underside of a leaf where oxygen and carbon dioxide can move.

Grana

The Grana is pancake-like stacks of the Thylakoid membrane.

Write and interpret the chemical formula for photosynthesis. Label the reactants and products

The chemical formula for photosynthesis is 6CO2 + 6H2O → C6H12O6 + 6O2. The reactants for photosynthesis are light energy, water, carbon dioxide, and chlorophyll (CO2 + H2O), while the products are glucose (sugar), oxygen, and water (C6 H12 O6 + glucose +O2).

Describe the significant events of the light dependent reaction (ETC). Include which reactants and products are involved. Highlight what will be released as a product and what will move on to the second stage, include where the process occurs in the chloroplast

The purpose is to capture energy from the sun and store energy in "energy-carrying molecules" (ATP and NADPH). It occurs in the Grana (specifically the Thylakoid membrane) where the chlorophyll is stored. Energy from sun is passed down the electron transport chain and is stored in the bonds of ATP and NADPH. Water molecules are then split into hydrogen and oxygen. Lastly, Oxygen is released as a waste product.ATP, NADPH, and Hydrogen (H+) leave the Grana and go into the Stroma for the next stage.

Describe the significant events of the light independent reaction (Calvin Cycle). Include which reactants and products are involved. Highlight what will be released as a product and what will move on to the second stage, include where the process occurs in the chloroplast

The purpose is to use the energy from the "energy-carrying molecules" from the light-dependent reaction to make sugar (glucose). It occurs in the stroma and is also known as the Calvin cycle. The chemical reactions powered by ATP and NADPH combine H+ (from water) with CO2 to form sugar molecules (glucose = C6H12O6). It then uses CO2 (and H+ from water) and makes glucose.