Chapter 2 Lesson 4 Cells and Energy

Quick quiz 1. During Cellular Respiration, where are the areas in the cell the reactions take place? 2. What is produced during glycolysis? 3. Cellular respiration occurs in 2 parts of a cell _____________and the ______________. 4. When talking about the second step of cellular respiration what are the two waste products in this is step are _______and carbon dioxide are given off.

quiz Where does the first step of cellular respiration takes place? Where the second step takes place? What is the first step of Cellular respiration?

Lesson 4 Terminology Cellular Respiration Glycolysis Fermentation Photosynthesis

Content purpose: SC.8.L.18.1 Describe and investigate the process of photosynthesis, such as the roles of light, carbon dioxide, water and chlorophyll, production of food release of oxygen. SC.8.L.18.2 Describe and investigate how cellular respiration breaks food to provide energy and releases carbon dioxide.

Take a ponder How does cell make energy? How do some cells make food molecules? What is produced during glycolysis?

In animal cells…. Animal cells have semi-permeable outer membranes that allow some molecules, such as the sugars and fats that are necessary for the creation of energy, to enter the cell. Once these molecules are inside the cell, the bonds that hold them together are gradually broken down. Each time a bond is broken, it releases energy that the cell can either burn immediately or store for later use. Energy that is stored is reassembled in the form of ATP molecules. These molecules have bonds that are easy to break quickly whenever the cell needs energy.

In plant cells…… Plants get the nutrients necessary for growth from molecules in the soil, water and air. However, unlike animals, they are not able to actively take in more nutrients in the form of food, so they need an alternate source of energy to create the chain reactions that break down the bonds of molecules to create energy for each cell. This energy comes from the sun, and plant cells are able to harness it using a chemical called chlorophyll, which enables photosynthesis.

Reactions Reactions in the: Cytoplasm Mitochondria Chloroplasts

Cellular Respiration Chemical reaction that convert the energy in food molecules into ATP. Occurs in 2 parts of a cell Cytoplasm and the Mitochondria.

Cellular Respiration Also occurs in the cytoplasm and mitochondria. Convert the energy in food molecules into ATP.

Glycolysis This is the FIRST step in Cellular Respiration that takes place in the cytoplasm. It’s when glucose molecules are broken down, into smaller one. Produces ATP.

Mitochondria This is the Second Step. This requires oxygen. Two waste products in this is step are water and carbon dioxide are given off. CO2 released by cells as waste product is used by plants and some unicellular organisms, in photosynthesis.

Photosynthesis Recall that photosynthesis uses light energy and CO2 and makes food energy and releases oxygen. This food energy is stored in the form for glucose.

FERMENTATION A reaction used to obtain energy from food when oxygen level are low. Occurs in cytoplasm….. not mitochondria

FERMENTATION Fermentation complements glycolysis and makes it possible for ATP to be continually produced in the absence of oxygen. By oxidizing the NADH produced in glycolysis, fermentation regenerates NAD+, which can take part in glycolysis once again to produce more ATP.

Fermentation – 2 types 1. Lactic - Acid Fermentation 2. Alcohol Fermentation

Lactic Acid Fermentation Glucose is converted to ATP

Alcohol Fermentation Some types of Bacteria and yeast make ATP through A.F. Instead of producing Lactic Acid, Alcohol fermentation an alcohol called ETHANOL and CO2 (carbon dioxide)