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Chemistry of Life Life’s chemistry is based largely on Organic Molecules. --molecules must contain both C and H --can contain more than just C and H --those.

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Presentation on theme: "Chemistry of Life Life’s chemistry is based largely on Organic Molecules. --molecules must contain both C and H --can contain more than just C and H --those."— Presentation transcript:

1 Chemistry of Life Life’s chemistry is based largely on Organic Molecules. --molecules must contain both C and H --can contain more than just C and H --those that contain only C and H are called Hydrocarbons. Example of a hydrocarbon is methane, aka biogas or gut gas. It is made from 1 C and 4 H. Methane is emitted from the Bacteria of ruminant animals and those found in rice patties. It is also emitted by humans as a gas coming out either end.

2 Most of the important molecules in living organisms have long chains of carbon molecules forming a backbone for other atoms to attach to. These carbon atoms can also attach to carbon atoms of other molecules to form very large, or macro molecules. Dehydration Synthesis: -used to build large molecules from small ones. -a single water molecule is removed from the two large molecules…an H+ from one and OH- from the other. -they join at this point -this example shows amino acids joining to form a protein

3 Molecules can also be broken down. To do this, reverse the process used during dehydration synthesis…instead of taking a water molecule away, add one!! This process is called Hydrolysis and it is used to break a large molecule into many smaller one that can be used to build with.

4 4 Major Groups of Macromolecules Play an Important Role in Living Organisms. 1.Carbohydrates 2.Lipids 3.Proteins 4.Nucleic Acids Carbohydrates: -Mainly C, H, and O in a 1:2:1 ratio. -General chemical formula is (CH 2 O)n with n = any # -Source of “quick energy” for the body -Found in many foods we consume like pasta, bread, cakes, cookies, pizza, sugared drinks, beer Monosaccharides = simple sugars -simplest class of carbs -sugars such as glucose (blood sugar) and fructose (fruit sugar)

5 Disaccharides = two sugars -two monosaccharides joined by dehydration synthesis -most common disaccharide is sucrose = glucose + fructose “table sugar” made from sugar cane or sugar beets. -lactose = glucose + galactose…”milk sugar” found in all dairy products. Some people lack the enzyme to help break down lactose in their body and are called “lactose intolerant.” -maltose = glucose + glucose…”malt sugar” found in malted milk balls, malt for milk shakes, and brews. Polysaccharides = many sugars -long chains (100’s to 1000’s) of monosaccharides Examples:

6 Starch- plant storage sugar. -plants make sugars in leaves and transport to storage area like roots or fruits or grains. -pastas and breads are considered “high starch” foods Glycogen- animal storage sugar. -animals store in liver until needed and then convert it to glucose Cellulose- “fiber” -forms cell walls of plants -largely indigestible…provides fiber for most organisms and helps keep them “regular” -ruminants can digest cellulose because they have an extra stomach, the “rumen,” which contains microorganisms that break down the cell walls of plants. When the plant cells pass into the next stomach, digestion occurs as normal.

7 Cows and giraffes Goats and Deer Ruminants Notice how large the rumen is

8 Chitin = outer shell of insects, crabs, lobster, crayfish, etc. these organisms lack a skeletal system and use the chitin shell for support and protection. When you step on a bug and it goes “crack” you have crushed some chitin!! Chitin is non-biodegradable meaning it does not break down in the ground over time like most parts of organisms. This characteristic is important in the manufacturing of suturing thread used to put stitches in you when you cut yourself. Think about it…it is strong and won’t break down over time during the healing process so it allows the skin to heal and then you can remove it. Next time you get stitches, ask the doctor if he is using the traditional “cat gut” or if he is using “chitin.”

9 Lipids: -mainly C and H. Contain very little O. -source of long term energy storage for the body -lipids have 6x as much energy as carbs but are much harder for the body to break down. -also serve as protective layers (think whale blubber) and precursors of larger molecules -are hydrophobic…meaning they fear water. Fats— -class of lipids found in many foods we consume -consist of one fatty acid and three glycerols joined by dehydration synthesis. (triglyceride) -see Figure 3.15, pg. 42 -two classes of fats…

10 Saturated Fats— -have all C atoms completely covered with H atoms. The molecule is “saturated” and is not easily broken down. -are solids at room temperature. When in fridge, they become “bricks” and are hard to use -main source is animal fats such as lard and real butter -tend to build up in arteries as plaque because they are not broken down. Lead to “arthrosclerosis” or plugged arteries. Heart pumps same amount of blood through blocked artery but works much harder and heart attack occurs

11 Unsaturated Fats— -C atoms are not completely covered by H atoms. Some double bonds can readily bond with other atoms to allow hydrolysis to occur. -still not good to consume in large amounts -found mostly in plant products…peanut oil, sunflower oil, vegetable oil, corn oil, canola oil -generally liquid at room temperature…will not freeze. -reindeer in artic have pockets of unsaturated fats in their hooves to prevent them from freezing What about Hydrogenated Vegetable Oil? Where do you find it at? Is it good for you? -most “spreadable” butters are plant oils that have been hydrogenated… -makes them more aesetic to use at the table but less healthy for your body.

12 Waxes— -protective coverings for plants and animals -where do we find them? -what do they protect against? Phospholipids— -important components of the cell membrane -learn more about them in the next unit Steroids— -have ring shape instead of linear shape -classified as lipids because they are hydrophobic -Cholesterol is important to body as part of cell membrane and ingredient in sex hormones estrogen and testosterone ey/apbio/phospholipid.gif

13 Anabolic steroids— “not from the body” -variants of male testosterone. -build up bone and muscle mass -cost is great…many side effects…”roid rage” common -can suffer liver damage -build manly muscles in women -reduced testicle size in men iver_damage.jpg

14 Proteins: -mainly C, H, O, and N -building blocks are amino acids (20 common aa’s build an infinite number of proteins) -protein shape determines function -seven different classes of proteins do many different jobs Classes of Proteins: -structural proteins used for support…hair and spider webs, horns and feathers, tendons and ligaments are all strong -contractile proteins found in muscles and are like elastic…allow muscle to expand and contract without losing shape

15 -transport proteins found many places to transport materials throughout the body…hemoglobin is an example and transports oxygen from your lungs throughout your body Signal proteins- -relay messages from one part of the body to another. -hormones are a good example…they help start and stop processes in the body by their release

16 Storage proteins- -store amino acids to be used for development of young organisms…such as a seed or an egg. Defense proteins- -antibodies in your immune system -each antibody will be specific for a different “bug” -will only attack what it is programmed to -flu, tetanus, hepatitis vaccines all have relatively “harmless” versions of the “bugs” that are introduced into your body to help build up an antibody army against it so when you come into contact with the real thing your body is ready to fight! antibodies-formation.jpeg

17 Enzymes— -very important class of protein -govern virtually every system in the body -speed up chemical reactions without becoming part of the reaction…thus, one enzyme can speed up thousands of chemical reactions. -called “catalysts” -lower the “activation energy” or the amount of energy that is needed to start a reaction. When a protein undergoes a shape change, it loses its ability to function properly. This is called DENATURING. These eggs do not have the same function after heat is added to them. I doubt cooked eggs can produce a baby chick!!


19 Nucleic Acids: -information storage molecules most common are DNA and RNA, ATP -contain “directions” for building proteins, supply cell energy DNA -located in the nucleus of the cell -made up of nucleotides 3 part molecule: Phosphate Sugar (2) Deoxyribose in DNA Ribose in RNA Nitrogen Base (4) Adenine ~ Thymine Cytosine ~ Guanine -all genetic information written in 4 letter alphabet A, T, C, G RNA -messages carried to cytoplasm, amino acids connected to make protein by different RNA types. ATP - located throughout the cell where energy processes take place. some cells have more ATP than others based on activity.

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