Ch 4.1, 4.2, 9.2-9.3

Photosynthesis and Biogeochemical Cycles

Autotroph

Organism that is able to capture energy from sunlight or chemicals and use it to produce its own food from inorganic compounds (also called a producer)

Heterotroph

Organism that obtains food by consuming other living things (also called a consumer)

Primary Producer

First producer of energy-rich compounds that are later used by other organisms

Consumer

Organism that relies on other organisms for its energy and food supply (also called a heterotroph)

Photosynthesis

A process used by plants and other autotrophs to capture light and energy and use it to power chemical reactions that convert carbon dioxide and water into oxygen and energy-rich carbohydrates, such as sugars and starches

Detritus

Material made up of decaying bits of plant and animal material

Chemosynhesis

Process in which chemical energy is used to produce carbohydrates

Food chain

A series of steps in an ecosystem in which organisms transfer energy by eating and being eaten

Food web

Network of complex interactions formed by the feeding relationships among the various organisms in an ecosystem

Phytoplankton

Photosynthetic algae found near the surface of the ocean

Biomass

Total amount of living tissue within a trophic level

Trophic levels

Each step in a food chain or food web

Ecological pyramid

Illustration of the relative amounts of energy or matter contained within each trophic level in a given food chain or food web

Types of ecological pyramids

Energy pyramid: shows how much energy is transferred from one trophic level to the next.

Biomass pyramid: shows the total mass of living tissue in each trophic level.

Numbers pyramid: gives a count of how many individual organisms are at each trophic level.

ATP

Compound used by cells to store and release energy

ADP

A lower-energy molecule that can be converted into ATP by the addition of a phosphate group

Energy

The ability to cause change or work

Potential energy

Stored energy

Scavenger

A carnivore that feeds on the bodies of dead organisms (consumer)

Carnivore

A consumer that eats only animals

Herbivore

A consumer that eats only plants

Omnivore

An animal that eats both plants and animals (consumer)

Decomposer

Organisms that chemically break down dead organisms and then absorb the resulting organic matter (decomposers are often bacteria or fungi)

Detritovore

organism that feeds on plant and animal remains and other dead matter

Pigment

Light-absorbing molecules used by plants to gather the sun's energy

Chloroplast

An organelle found in plant, algae, and some bacteria cells where photosynthesis occurs

Thylakoid

Part of the chloroplast where light dependent reactions take place

Stroma

Part of the chloroplast where the Calvin Cycle (light independent reactions) take place

Stoma/stomata

Small opening in the epidermis of a plant that allows carbon dioxide, water, and oxygen to diffuse into and out of the leaf

Granum/grana

A stack of thylakoids in a chloroplast

Chlorophyll

A green pigment found in chloroplasts that helps absorb energy from the sun

Inputs and outputs in a light-dependent reaction

Inputs: Water and Sunlight

Outputs: Oxygen, ATP, NADH

Inputs and outputs in a light-independent reaction

Input: Carbon dioxide, NADPH, ATP

Output: Glucose, ADP +P, NADP+

What is ATP Synthase

H+ ions travel through ATP synthase. ATP Synthase uses potential energy from the proton gradient to combine ADP with inorganic phosphate, which combines to form ATP

What from the light-dependent reaction is needed for the Calvin Cycle (light-independent reaction)

ATP and NADPH

Electron carrier

A compound that can accept a pair of high-energy electrons and transfer them, along with most of their energy, to another molecule

What happens to NADP+ at the end of the electron transport chain

It accepts an electron, forming NADPH

Where does the mass of a tree come from

Carbon dioxide

What environmental factors affect the rate of photosynthesis

Light intensity, CO2 concentration, temperature

First law of thermodynamics

Energy can be transferred and transformed, but it cannot be created or destroyed

Second law of thermodynamics

Energy cannot be converted without the loss of usable energy

How much energy is passed through each trophic level of an energy pyramid

10%

What role do pigments play in the process of photosynthesis

Some pigments are able to absorb certain lights more than others, allowing a plant to grow more

Why is water split

To provide electrons for the electron transport chain

Three steps of the Calvin Cycle

1. Carbon fixation

2. Reduction

3. Regeneration

What molecule is regenerated at the end of the Calvin cycle to be reused in the next cycle

RuBP

What is the role of NADPH in the Calvin cycle

To provide electrons for the reduction of carbon dioxide

Where is the energy from ATP stored

The bonds between the phosphate groups

What is the relationship between ATP and ADP

With an input of energy, ADP combines with a phosphate group to become ATP

A mushroom gains its energy by decomposing the tissues of dead organisms. Should mushrooms be classified as autotrophs, heterotrophs, in both groups, or in neither group, and for what reason

They are heterotrophs because their food is made by other organisms