Molecules

Kelly Diep

Ms.Malonek

Period 1

Shapes of Molecules

           A molecule is the smallest unit of a compound that can exist alone and keep the properties of that compound. Molecules are made up of one or more atoms. If they have more than one atom, the atoms can be the same or different, In living organisms, molecules like DNA and proteins, are made up of thousands of atoms. The three-dimensional shape of a molecules is an important trait. The shape depends on the preferred spatial orientation of covalent bonds to atoms having two or more bonding partners. There are many different kinds of shapes of molecules like linear, triganol planar, tetrahedral, bent, and more.  Lewis structures were drawn for several small molecules and ions with different combinations of single, double, and triple bonds. Some examples of linear molecules are H2 and HCI. All diatomic molecules are linear in shape. The chemical formula of a molecule or compound shows how many atoms of each element are in one molecule of the compound. These are written by putting the element's symbol next to each other. A subscript is a small number after the symbol of that element. For example, the formula for carbon dioxide is CO2  meaning that there is one carbon atom and two oxygen atoms.

Reference:
http://www.ausetute.com.au/shapemol.html
http://www.chem.ufl.edu/~myers/chm2045/shapes.htm

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Enzymes

Kelly Diep
Ms. Malonek
Period 1-Biology
9/3/14

Digestive Enzymes

        Digestive enzymes are enzymes that break down polymeric macromolecules into smaller building blocks to make their adsorption in the body easier. The digestive enzymes are very diverse and are found in digestive tracts of animals and humans. Their purpose is to aid in the digestion of food. 

       

        These enzymes are also found in the saliva secreted by salivary glands in the stomach, pancreatic juice, and in the intestinal secretions. Digestive enzymes are grouped based on their target substrates. Proteases and peptidases split proteins into small peptidases and amino acids. Lipases split into three fatty acids and a glycerol molecule. Carbohydrases split carbohydrates like sugar and starch into simple sugars.Nucleases split nucleic acids into nucleotides. 

        The main locations of digestion in the human body are the oral cavity, stomach and the small intestine. In the oral cavity, complex food substances must be broken down into simple, soluble, diffusible substances before they can be absorbed. Also, salivary glands secrete an array of enzymes and substances to help with digestion and disinfection. There are two kinds of salivary glands: serous and mixed glands. Serous glands produce a secretion rich in water, electrolytes, and enzymes. Mixed glands have both serous and mucous glands.

        The enzymes secreted in the stomach are called gastric enzymes. The stomach plays a major role in digestion by mixing and  crushing the food. Pepsin is the main gastric enzyme which breaks down protein in food into smaller particles. Pancreas is both an endocrine and exocrine gland. It functions to produce endocrinic hormones released in the circulatory system. Thus, digestive enzymes have an important role in our bodies.

Reference:
Info-http://whole9life.com/2012/09/digestive-enzymes-101
        http://health.usnews.com/health-news/blogs/eat-run/2013/04/23/digestive-enzymes-help-or-hype/
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