Summary of Chapter 5.3

Vocabulary:
lipid: one of a class of water-avoiding compounds
hydrophobic: water fearing
fat: organic compound consisting of a three-carbon back (glycerol) attached to three fatty acids
saturated fat: fat in which all three fatty acids chains contain the maximum possible number of hydrogen atoms
unsaturated fat: fat with less than the maximum number of hydrogens in one or more of its fatty acid chains
steroid: lipid molecules with four fused carbon rings
cholesterol: steroid molecule present in the plasma membranes of animal cells

Lipids include fats and steroids. Lipids are hydrophobic. Fats are stored for later use and the fatty tissues cushion your organs. All the carbon atoms in the fatty acid chains form single bonds with each other, and the rset of their bonds are with hydrogen atoms.

animal fats: lard and butter (both are saturated)

unsaturated fats: fruits, vegetables, fish, corn oil, olive oil, and other vegetable oils

Steroids circulate in your body as chemical signals. Cholesterol is the best-known steroid. Cholesterol has a bad reputation because high levels of cholesterol can increase risks of heart and blood vessel diseases.
Concept Checks:

1. What property do lipids share? Lipids share the property of being hydrophobic ( meaning water-avoiding ).

2. What are the parts of a fat molecule? A fat molecule consists of a three-carbon backbone called glycerol attached to three fatty acids that contain long hydrocarbon chains.

3. Describe two ways that steroids differ from fats. In the body, fats store energy for later use as fatty tissues cushion your organs and steroids circulate around your body as chemical signals. Fats are of glycerol attached to three fatty acids while a steroid is a lipid where the carbon skeleton forms four fused rings.

4. What does the term unsaturated fat on a food label mean? Unsaturated fat means that it contains less than the maximum number of hydrogen atoms in one or more of its fatty acid chains because some of the carbon atoms are double bonded to each other.

Summary of Chapter 5.2

Vocabulary:
carbohydrate: an organic compound made of sugar molecules
monosaccharide: simple sugars that contain just one sugar unit
disaccharide: sugar with two monosaccharides
polysaccharide: long polymer chain made up of simple sugar monomers
starch: a polysaccharide found in plant cells that consists entirely of glucose monomers
glycogen: excess sugar in a form of a polysaccharide
cellulose: polysaccharide consisting of glucose monomers that reinforce plant-cell walls

This section discusses about the definition of carbohydrates and how carbohydrates provide energy. In a dehydration reaction, cells create two monomers, becoming disaccharides ( the main type of disaccharide is sucrose ). Long polymer chains of simple sugar monomers are polysaccharides, such as starch, a polysaccharide found in plant cells consisting entirely of glucose monomers. When plants break down starch molecules, the glucose becomes available to use. Animals and humans store sugar in a type of polysaccharide called glycogen. Just like starch, glycogen is also a chain of many glucose monomers. When the glycogen is needed in animals, the body breaks down the energy from glycogen granules releasing glucose. Cellulose are polysaccharides that protect cells and stiffens plants. Cellulose is also made of glucose monomers. Most animals and people cannot digest cellulose because they do not contain the molecule necessary to break the bonds of the glucose monomers in glucose. All carbohydrates are hydrophilic. Starch comes from plants and glycogen comes from humans and animals.

Concept Checks

1. Explain the difference between a monosaccharide and a disaccharide. Give an example of each. Monosaccharides contain one sugar unit ( simple sugars ) and a disaccharide contains two sugar units ( double sugars ). An example of a monosaccharide is fructose and an example of a disaccharide is sucrose.

2. Compare and contrast starch, glycogen, and cellulose. Starch, glycogen, and cellulose are all polysaccharides. Glycogen is found in animals and humans and a glycogen polymer is more highly branched than starch polymer. Cellulose is found in plants, just like starch, but they work as building materials. Starch, glycogen, and cellulose are all made of glucose monomers.

3. How do animals store excess glucose molecules? Animals store excess glucose molecules in glycogen. When the body needs energy, it breaks down glycogen granules, releasin glucose.

Summary of Chapter 5.1

Vocabulary:
organic molecule: carbon based molecule
inorganic molecule: non carbon based molecule
hydrocarbon: organic molecules that are composed of only carbon and hydrogen
functional group: a group of atoms within a molecule that interacts in predictable ways with other molecules
hydrophilic: attracting water molecules
monomer: small molecular unit that is the building block of a larger molecule
polymer: long chain of small molecular units (monomers)

Carbon is the main ingredient of organic molecules. They may form bonds with other carbon atoms to make an endless variety of carbon skeletons. Organic molecules are important, such as hydrocarbon. Hydroxyl groups are hydrophilic so they often are surrounded by water molecules in an aqueous environment. Large molecules are built by monomers. Cells connect monomers into polymers and every living cell has thousands of polymers. When a monomer is added to a polymer, a water molecule releases, resulting into a dehydration reaction. . Polymers can also be broken down to receive their energy. Cells break bonds between monomers by adding water to them. A hydrolysis reaction is when water is used to break down the polymer. Water is removed to build a polymer, and water is added to break it down.

Concept Check
1. Draw a molecule that has a three-carbon skeleton and a hydroxyl group on the middle carbon. (Hint: The molecule's formula is C3H80)
2. Explain the connections between monomers and polymers. Monomers are small molecular units that link together into long chains called polymers.
3. What molecule is released during the construction of a polymer? What is this reaction called? Each time a monomer is added to a chain, a water molecule is released. This reaction is called a dehydration reaction.
4. Draw at least three ways in which five carbon atoms could be joined to make different carbon skeletons.

natasha > who?

Helloooooooooooooooooooooooooooooooooooo
My name is Natasha YuChia Hu (NYCH) and I'm Taiwanese.
I'm pretty short for my age, but I AM trying to grow ( ADD OIL ! )
I'm turning 15 this year at the 31st of the Christmas month.
I have a younger brother named Dion and he just started 7th grade. There are times where we never get along well, but also times where we seem like best friends.
I was born in HongKong and I lived in cities of Shenzhen and Qingyuan of China until a year before preschool where I went to live with my mom's friends in Canada and the US for a year.
I came back to Guangzhou for preschool in AISG. I was here until after kindergarten because I went to Canada for 2 years. I came back to AISG in 3rd grade. I've been living in Guangzhou for most of the time in my life.

LOVES TO:
to eat different types of food (favorites: Korean, Japanese, and Taiwanese). I eat a lot, you should see me eat basically everything in a buffet ( ahh, SHANGRILA+WESTIN)My favorite dessert is PUDDING, and I love it very very very much.