Cellular Respiration

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Cellular Respiration Objectives

List the products of photosynthesis that are critical for human survival.
Describe cellular respiration, including where it occurs in cells.
Contrast cellular respiration with systemic respiration.

Humans have to consume other organisms as a source of energy and nutrients. We’re going to focus first on how cells convert sugar molecules into usable energy.

In the process of photosynthesis, plants, algae, and some bacteria can convert carbon dioxide and water in the presence of sunlight into sugar and oxygen. This primarily occurs in plant (or algae) chloroplast organelles.

They immediately use some of that sugar and oxygen to power cellular activity in the process of cellular respiration. This occurs in the mitochondria organelles.

Fortunately for us, plants (plus algae, and some bacteria) produce excess oxygen and have sugar in their bodies that we are able to consume.

Our own mitochondria also carry out cellular respiration; converting sugar and oxygen into usable ATP energy. Water that is produced is recycled by the cell for other uses. And carbon dioxide that is produced has to be eliminated by the body.

Respiration occurs in both plant and animal cells. In animals, tissues and organs are required to obtain the oxygen and sugar that plants can make for themselves.

This video provides an overview of cellular respiration.

Mitochondria in all complex-celled organisms, and chloroplasts in plants and algae, resemble free-living bacteria. The endosymbiotic theory states that mitochondria and chloroplasts in cells separately originated from one bacterial species engulfing (but not digesting) another.

The respiratory system is responsible for getting oxygen into the body and carbon dioxide out.

Multiple organ systems play a role in supporting cellular respiration:

Digestive System

Digests foods into nutrients that are absorbed into the blood.

Respiratory System

Bring oxygen to the blood, discards carbon dioxide.

Cardiovascular System

Moves nutrients, oxygen, and carbon dioxide from one place to another.

Cellular Respiration: cells converting oxygen and sugar to ATP energy (and carbon dioxide and water).

Systemic Respiration: the process of breathing air in and out, the work done by the respiratory system.

Science knowledge, like understanding the origin of mitochondria, accumulates over time due to a continual process of science discovery: exploration, description, and explanation.

Experimentation plays an important role in science knowledge development.

You will be designing an experiment for this guide’s media piece. This video walks through the basic experimental steps.

Start Your 5A Media Assignment here

In this media piece you are designing an experiment related to your body and/or activities. You do not need to conduct this experiment, this is establishing that you can design an experiment. If you do choose to conduct this experiment, it can be part of your body data collection that you will be analyzing later in the course.

Note: Use sense and care when considering self-experimentation. If testing variables, choose those that you hypothesize (predict) will improve health and avoid those that may decrease health. If unsure, seek professional assistance as needed.

You are turning in:

Your experimental design which includes: (1) the research question, (2) variable(s) being tested, (3) hypothesis, and (4) experimental procedure. The experimental procedure includes (4a) the control, (4b) treatment(s), (4c) any materials needed, (4d) what you will be doing, (4e) the type of data that will be collecting, and (4f) any safety considerations.