Part 2 Unit 3 Essential Content - Google Docs

Matter

The material that makes up all living and nonliving things, composed of atoms that combine to form molecules.

Energy

The capacity to do work; required by all living organisms to do biological work. Includes light, chemical, and thermal (heat) forms.

ATP

A small molecule used by cells to store energy that can be released to do biological work; often referred to as the energy molecule for cells; stands for Adenosine Triphosphate.

Aerobic Cellular Respiration

The process by which living organisms produce ATP, using glucose and oxygen as reactants to produce carbon dioxide, water, and cell energy (ATP).

Mitochondria

The organelle in eukaryotic cells responsible for energy production, where aerobic respiration occurs.

Anaerobic Cellular Respiration

A process by which cells produce ATP without oxygen, also called fermentation. Less efficient than aerobic respiration.

Trophic Level

A level of feeding, or a position in the food web, which is determined by an organism’s source of food.

Producers

The first trophic level; autotrophic organisms that produce food for themselves using energy from the sun or inorganic chemicals.

Consumers

Heterotrophic organisms that must take in food for nutrition.

Primary Consumers

The second trophic level; herbivores that feed on plants/producers.

Secondary and Tertiary Consumers

The third and fourth trophic levels; consumers that feed on other consumers, or both producers and other consumers (omnivores).

Food Webs

A way to display feeding relationships in an ecosystem, consisting of multiple overlapping food chains. Arrows show feeding relationships and transfer of energy.

Ecological Efficiency

The concept that only about 10% of the energy contained in an organism is passed to the next trophic level when it is consumed (10% rule). The other 90% is 'lost' as heat or used for biological work.

Photosynthesis

The process by which producers transform light energy into stored chemical energy in the form of glucose, using carbon dioxide and water as inputs and producing glucose and oxygen as outputs.

Chloroplasts

The organelle in eukaryotic cells that contains chlorophyll and allows cells to 'gather' energy from light, where photosynthesis occurs.

Stomata

Microscopic pores found on the underside of leaves in some plants that allow for the exchange of gasses between the leaf and the atmosphere.

Vascular Tissue

A transport system in some types of plants for the movement of water (xylem) and glucose (phloem).

Decomposers

Living organisms such as bacteria and fungi that break down wastes and dead organisms, allowing nutrients to be returned to the soil and atmosphere for reuse.

Carbon Cycle

The cycling of carbon is driven by the processes of photosynthesis (carbon sink) and cellular respiration (carbon source).

Nitrogen Cycle

Nitrogen is an element needed by plants to help build proteins and nucleic acids. Soil bacteria convert atmospheric nitrogen to a form that can be taken in by plant roots.

Phosphorus Cycle

Phosphorus is an element needed by plants to build nucleic acids. Plants take in phosphorus from the soil, which can then be transferred to animals when plants are consumed.

Sustainability

Refers to the responsible use of natural resources to meet current needs without compromising the ability of future generations to meet their needs.

Environmental Impacts of Food Production

Increased food production requires increased use of natural resources (water, soil minerals, land, fossil fuels) and chemicals (fertilizers, pesticides, herbicides), which can negatively impact the environment.