THE CHEMISTRY OF FOODPLTW – PBS

Chapter 2.2 Study Guide

Food Testing Lab

Know the chemical tests used to detect each substance Glucose – Use Benedict’s solution, heated,

green/yellow is positive, stays blue is negative Starch – Use Iodine, if turns black is positive, if stays

brown/amber it’s negative Protein – Use Biuret Stain, if turns pinkish/purple it’s

positive, if stays a bluish-clear then negative Lipids – Use the brown paper towel test, if it leaves a

clearish oil spot then it’s positive, if the liquid dries then it’s negative.

Food Testing Lab

Know the description and role for each of the molecules we tested Starches – are complex carbohydrates which are a

source of energy Glucose – is a simple carbohydrate which is a source

of energy Protein – Critical for building tissues, fighting disease

(immunity), and facilitating chemical reactions Lipids – such as fats and oils, they help in cell

membrane production and hormone production

Food Testing Lab

Be able to discuss the role of Anna’s last meal (heavy in starches and lipids) and how it could have contributed to her death as a type 1 diabetic.

Describe the role of using water during the initial testing of the indicators.

Describe the purpose of doing the part 1 of the lab (testing known solutions against water) prior to doing the actual testing of the foods.

Food Labels

Be able to discuss the definition and importance of EACH of the nutritional terms on your nutritional terms chart. (see activity 2.2.2)

Be able to analyze a food label for content as well as health levels. Make sure to know recommended values so you can determine if a particular ingredient is too high or too low.

Describe key features of a HEALTHY diabetic diet. How does this relate to Anna Garcia???

Explain the reasons for limiting things such as saturated fat, cholesterol, and sodium.

PLEASE REVIEW THE 2.2.3 CHEMLIFE POWERPOINT FROM THE LMS. THE MATERIAL

PRESENTED IN THIS POWERPOINT WILL BE COVERED EXTENSIVELY ON THE TEST. YOU ALSO

SHOULD HAVE NOTES OVER THE POWERPOINT FROM WHEN IT WAS COVERED IN CLASS.

USE THESE HELPFUL VIDEOS ALSO: BIOLOGICAL MOLECULES

MOLECULES OF LIFEATOMS & THE PERIODIC TABLE

CHEMICAL BONDS

Biochemistry of Life

Dehydration vs. Hydrolysis Reactions

Dehydration synthesis – when larger molecules are form by connected smaller molecules. During this process an -H and –OH are removed from the smaller molecules so they have an opening to connect. Thus the H, OH will combine together forming water (H2O). Thus, Dehydration synthesis is the creating of larger molecules by the removal of water.

Hydrolysis Reactions – When larger molecules need to be broken down into smaller molecules, water will break the bonds between the two molecules and attach to the open spaces. Thus, hydrolysis reactions is the process of using water to break down larger molecules into smaller molecules.

http://education-portal.com/academy/lesson/hydrolysis-dehydration-and-ionic-reactions-definitions-examples.html#lesson

Chemical Bonds and Energy

What is the relationship between chemical bonds and energy?

Explain how the body gets the energy it needs to function from the food we eat.

Compare and contrast saturated and unsaturated fatty acids

Which would give you more energy: monosaccharide, disaccharide, or a polysaccharide?

Energy in Food

Energy from carbohydrates is released in the cells through a process called cellular respiration. The energy produced is called ATP (Adenosine Triphosphate)

calorie – the amount of energy needed to raise the temperature of 1kg of water 1°C (this is a chemistry calorie)

Calorie – food calories (actually is 1000 calories)Energy in food is found by burning the food to

heat water and measuring the increasing in temperature of the water – known as calorimetry