Lab Exam 1

Acid-Base Behavior

Acids and bases are measured on a scale called pH. pH, or potential hydrogen. Neutralization of an acid or base is a technique frequently used for the proper disposal of the compound.

nucleic acids

All genetic material is composed of (DNA). Another nucleic acid, RNA, functions in the production of proteins and other cellular processes.

Ingestion of chemicals

Call 911 or "Poison Control" at 1-800-222-1222 (24 hours). Check the SDS immediately.

Fire

Fires in a laboratory are often contained in pieces of glassware, such as a beaker. You should not move a beaker that has a chemical burning in it. Instead, extinguish the fire simply by covering the mouth of the beaker with a thin, curved piece of glass (called a watch glass) and turning off the source of the flame. A glass plate or pie pan can also work in place of a watch glass. If the fire is not easily covered, use a fire extinguisher. If the fire is too large to extinguish quickly, evacuate the building and call the fire department. Clothing fires can be extinguished in a safety shower if one is close by. If not, you will need to STOP, DROP, and ROLL to quickly smother the fire.

Burns

Flush the area with cool running water for 20 minutes. Medical attention may be necessary.

Chemical Spills on a Person

If a spill covers a large area, the typical course of action is to remove all contaminated clothing while the person is under a safety shower or home shower. If it is a small area, flush it immediately with a large volume of water, and then wash it with soap. Check the SDS for the specific spilled chemical and follow all instructions. Medical assistance may be necessary.

Macromolecules are

The term "macromolecule" simply means a large molecule. Recall that molecules are substances that contain two or more atoms bonded together. The same four types of macromolecules are used by all living organisms for cellular metabolism and reproduction. These common biological macromolecules are lipids, nucleic acids, carbohydrates and protein. The properties they convey are of great importance to cell function.

Working With Chemicals (Cont.)

Use test tube caps or stoppers, not your finger, to cover test tubes when shaking or mixing. When diluting an acid, always pour the acid into the water. Never pour water into an acid; the heat of reaction will cause the water to explode into steam sometimes violently, and the acid may splatter. Handle flammable hazardous liquids over a pan to contain spills. Never dispense flammable liquids anywhere near an open flame or source of heat.

hydrogen bonding

result from the interaction of the positive region of one polar molecule and the negative region of another polar molecule. Although relatively weak bonds, these are extremely important in the maintenance of chemical structures. In fact, the double strands found in DNA as well water molecules are held together by hydrogen bonds. Adenine and thymine (nucleic acids found in DNA) are held together via two hydrogen bonds, and cytosine and guanine are held together by three.

Proteins

the most abundant macromolecule in living systems. Like lipids, proteins perform a variety of functions. For example, proteins are major components of tendons, ligaments and muscles in the human body.

lab safety equipment

A safety shower is used when a hazardous chemical is spilled on somone and the person is unable to rinse it off thoroughly in a sink or if a person's clothes catch on fire. Most safety showers are operated by pulling a chain. For the purpose of the experiments you will be performing, a standard home shower will function the same way. If a sink is insufficient to thoroughly rinse yourself, get to the nearest shower as quickly as possible. An eye wash is used if a harmful chemical is splashed into your eyes. It has two spouts positioned to to efficiently rinse both eyes at the same time. For the purposes of the experiments you will be performing, a standard faucet and sink will function the same way. If your eyes become irritated during an experiment, even if you think they have not been exposed to chemicals, find the nearest sink and flush water in your eyes for at least 20 minutes. If your sink has a hose, use it to rinse your eyes or face while making sure the water drains into the sink. You may also need to seek medical attention. A fire extinguisher is used to put out small to medium fires. If an experiment requires you to work with flames and you do not have a fire extinguisher in your home, keep containers of water easily accessible while you perform the experiment. Do not hesitate to call your local fire department and evacuate your home if a small fire growth to a large fire. A laboratory fume hood is used to remove harmful gases and fumes sometimes present when doing an experiment. You should always work in a fume hood whenever you are working with corosive, noxious, or flammable materials. The chemicals used in this kit will not require the use of a fume hood, but as a precaution, always work in a well-ventilated area.

When pouring a chemical:

Always hold the lid of the bottle between your fingers. Never lay the lid down on a surface, as this can contaminate the chemical supply Hold the containers away from your body while pouring.

Proper lab attire

Always wear the safety glasses, gloves, and apron provided in your PPE safety kit. Do not wear soft contact lenses while conducting experiments; lenses can absorb potentially harmful chemicals. Wear safety glasses at all times. Pull back and secure long hair. Do not eat, drink, chew gum, apply cosmetics, or smoke while conducting experiments. Remove all jewelry (rings, watches, necklaces, earrings, bracelets, etc.). Remove all loose clothing (jackets, sweatshirts, etc.), and always wear closed-toe shoes.

Chemical Spills on the Bench or Floor

Be sure to clean up the spill immediately. If a spill involves volatile or flammable materials, such as alcohol, make sure ALL flames in the work area are extinguished and spark-producing equipment is shut down. In the case of an acid spill, pour baking soda on the acid before cleaning it up. In the case of a base spill, pour vinegar on the base before cleaning it up. All other chemicals used in this manual can be wiped up without adding an acid or base to neutralize first. If you have any questions, check the SDS of the specific spilled chemical.

Laboratory safety rules

Conduct yourself in a responsible manner at all times in the area that you will be performing the lab work. Follow all written and verbal instructions carefully. If you do not understand a direction or part of a procedure, ask before proceeding. Do not eat, drink, smoke, or chew gum in the area where you will be performing your lab work. Do not use any laboratory equipment as containers for food or beverages. Perform only those experiments issued in your eScience labs kit. Unauthorized experiments are prohibited. Read all procedures thoroughly before starting each experiment. Observe good housekeeping practices. Work areas should be kept clean and tidy at all times. Bring only your laboratory instructions, worksheets, and/or reports to the work area. Other materials (books, purses, backpacks, etc.) should be stored in another area. Know the locations and operating procedures of all safety equipment, including the first aid kit, eyewash station (sink), safety shower, fire extinguisher, and fire blanket. Know where the fire alarm and exits are located. Always work in a well-ventilated area. Be alert and proceed with caution at all times in the area where you will be performing the lab work. Never point a test tube or any vessel that you are heating at yourself or anyone else, as it may explode. Do not "shake down" thermometers or use them as stirring rods. Thermometers break easily. Dispose of all chemical waste properly. Solid chemicals, metals, matches, filter paper, and all other insoluble materials are to be disposed of in the proper waste containers. Carefully read labels and equipment instructions before use. Set up and use the prescribed apparatus as directed in the laboratory instructions. Keep your hands away from your face, eyes, mouth, and body while using chemicals. Wash your hands with soap and water after performing all experiments. Clean (with detergent), rinse, and wipe dry all work surfaces (including the sink) and apparatus at the end of each experiment. Return all clean equipment in working order to the proper storage area. Ensure that all experiments are personally monitored at all times.

How to Respond to Accidents

Even if you follow all of the safety guidelines, accidents can still happen. Therefore, it is important to know how to respond to different types of accidents.

Working With Chemicals

Every chemical in your kit has a Safety Data Sheet (SDS) label and includes a hazardous materials rating, for health (how harmful it is to be exposed to the chemical), flammability (how easily the chemical will catch fire), and reactivity (how easily the chemical reacts or explodes at room temperature). The SDS rating for each area ranges from 0 to 4, with 4 being highly reactive, flammable, and dangerous to health, and 0 being not reactive at all, not flammable, and not hazardous to health. The chemicals included in your kit are rated at 1 or below and can be poured down a drain for disposal, but you should still wear PPE at all times when performing experiments. All chemicals in a laboratory should be considered hazardous. Never smell or ingest chemicals. If this occurs, seek immediate help. Never pipette anything into your mouth. Never remove chemicals or other materials from the laboratory area. To be sure you have the right substance, always read the label twice before taking anything from a bottle. Serious accidents can occur if the wrong chemical is used. To avoid future issues with identification or proper disposal, never place chemicals in an unmarked container. To avoid contamination and potential hydration problems, always put lids back onto chemical containers immediately. Be careful not to interchange lids among different chemical bottles.

Cuts and Wounds

If a chemical gets into a cut or wound, rinse it off immediately with a large amount of water. Refer to the SDS label on the container. Medical attention may be necessary.

Chemical Contact with Eyes or Face

If a chemical is splashed on your face and/or in your eyes, immediate attention is critical. Call for help and get to the nearest sink. If the chemical splashes on your face and you have safety glasses on, KEEP them on. Rinse the chemical from your face before you remove the safety glasses. If a chemical gets in your eyes, hold your eyes open and flush with water for at least 20 minutes. Even though you should not be wearing contact lenses in the lab, if you are, rinse your eyes thoroughly, remove your contacts, and continue to rinse your eyes. A doctor should examine your eyes as soon as possible.

Lab Clean-Up and Disposal

If a spill occurs, consult the SDS to determine how to clean it up. Never pick up broken glassware with your hands. Use a broom and a dustpan, and discard in a safe area. Do not use any part of the lab kit as a container for food. Safely dispose of chemicals. If there are any special requirements for disposal, they will be noted in the lab manual. When finished, thoroughly wash your hands and lab equipment with soap and water. Once an experiment is concluded, dispose of the remaining chemicals by pouring them down the drain with copious amounts of water. However, if the chemical is an acid or a base, you will need to neutralize it before pouring it down the drain. A neutralization reaction occurs when an acid and a base react to form water and a salt. The neutralization of a strong acid and a strong base has a pH equal to 7 (neutral and therefore safe).

organic vs inorganic molecules

In biology and chemistry, the terms organic and inorganic are used to categorize molecules. Molecules are defined as two or more atoms bonded together. Organic molecules contain carbon and are typically identified by the presence of carbon-hydrogen bonds. The human body is made up of roughly 27% organic molecules and 73% inorganic molecules. Carbohydrates (sugars) and proteins are examples of organic molecules (Figure 2). Ammonia (NH3), table salt (NaCl), and water (H2O) are all examples of inorganic molecules.

How to use a microscope

Microscope Carrying When moving your microscope, always carry it with both hands Grasp the arm with one hand and place the other hand under the base for support. Turn the revolving nosepiece so that the lowest power objective lens is "clicked" into position (This is also the shortest objective lens). Your microscope slide should be prepared by placing a coverslip or cover glass over the specimen. This will help protect the objective lenses if they touch the slide. Place the microscope slide on the stage and fasten it with the stage clips. You can push down on the back end of the stage clip to open it. Microscope CareLook at the objective lens and the stage from the side and turn the coarse focus knob so that the objective lens moves downward (or the stage, if it moves, goes upward). Move it as far as it will go without touching the slide! Now, look through the eyepiece and adjust the illuminator (or mirror) and diaphragm (Figure 3,Microscope Viewingat left) for the greatest amount of light. Slowly turn the coarse adjustment so that the objective lens goes up (away from the slide). Continue until the image comes into focus. Use the fine adjustment, if available, for fine focusing. If you have a microscope with a moving stage, then turn the coarse knob so the stage moves downward or away from the objective lens. Move the microscope slide around so that the image is in the center of the field of view and readjust the mirror, illuminator or diaphragm for the clearest image. Now, you should be able to change to the next objective lens with only minimal use of the focusing adjustment. Use the fine adjustment, if available. If you cannot focus on your specimen, repeat steps 4 through 7 with the higher power objective lens in place. Do not allow the objective lens to touch the slide! The proper way to use a monocular microscope is to look through the eyepiece with one eye and keep the other eye open (this helps avoid eye strain). If you have to close one eye when looking into the microscope, it's ok. Remember, everything is upside down and backwards. When you move the slide to the right, the image goes to the left! Do not touch the glass part of the lenses with your fingers. Use only special lens paper to clean the lenses. When finished, raise the tube (or lower the stage), click the low power lens into position and remove the slide. Always keep your microscope covered when not in use. Dust is the number one enemy!

Explain how different types of microscopes affect magnification and resolving power.

Microscope types can be broken down into three main categories: optical, electron and scanning probe microscopes. Magnification gives how many times the image has been magnified by the instrument. Resolving power gives the ability to separate between two closely placed objects. The resolving power is the quality or the sharpness of the image.

Handling Glassware and Equipment

Never handle broken glass with your bare hands. Use a brush and dustpan to clean up broken glass. Place broken or waste glassware in the designated glass disposal container. Fill wash bottles with only distilled water and use only as intended (e.g., rinsing glassware and equipment, adding water to a container). When removing an electrical plug from its socket, grasp the plug, not the electrical cord. Make sure your hands are completely dry before touching an electrical switch, plug, or outlet. Examine glassware before each use. Never use chipped, cracked, or dirty glassware. If you do not understand how to use a piece of equipment, ask for help. Do not immerse hot glassware into cold water. The temperature extremes may cause the glass to shatter.

If you have any doubt as to what you are supposed to be doing and how to do it safely:

STOP! Double-check this manual Contact your instructor Contact eScience Labs at www.esciencelabs.com/support If you have any questions or concerns regarding a chemical, the SDS for any chemical supplied by eScience labs can be found at www.esciencelabs.com/msds

Personal Protective Equipment (PPE)

Safety Glasses aare used to protect your eyes and should be worn at all times when performing experiments, even if you are not working with chemicals. Safety glasses can and should be worn over eyeglasses because safety glasses provide splash protection from both the front and the side. Gloves protect your hands from harmful chemicals or hot objects. They also keep your workspace from being contaminated. The type of glove needed will depend on the application. For example, oven mitts are worn to remove hot objects from an oven, while nitrile gloves are used when working with acids and bases. It is very important not to touch your workspace with gloves that have been in contact with harmful chemicals.. The apron functions like a laboratory coat. It helps keep chemicals from from getting on your clothes.

covalent bonding

can produce molecules that are either polar or non-polar. Some of the 20 amino acids found in proteins are non-polar and some are polar. When macromolecules are created, non-polar regions tend to be located close together.

Carbohydrates

commonly referred to as sugars. This class of organic compounds serves as one of the primary sources of metabolic energy. The carbohydrate monosaccharide subunit most commonly used for energy is glucose. Other useful carbohydrates include maltose, lactose, sucrose, and starch.

Lipids

have many functions within living organisms including energy storage, membrane structure, and aids in the formation of internal cellular components.