7C - Muscles and Bones
1. Your body needs oxygen (O2) to break down food molecules and produce energy, and it needs to get rid of carbon dioxide (CO2), which is a waste product of cellular respiration. Oxygen is used to generate ATP (adenosine triphosphate), which is the primary source of energy for your body's cells.
2. Your breathing rate and pulse rate can change depending on your activity level. During exercise or other physical activity, your muscles require more oxygen, so you breathe faster and your heart beats faster to deliver more oxygen-rich blood to your muscles. This is called an active state. When you are at rest, your breathing rate and pulse rate are slower because your body requires less oxygen.
3. A drug is any substance that has a physiological effect when introduced into the body. Drugs can be used for medical purposes, such as treating or preventing illness, or they can be used recreationally or illegally.
4. The human arm consists of three main parts: the upper arm (humerus), the forearm (radius and ulna), and the hand (carpals, metacarpals, and phalanges). The muscles that help move the arm include the biceps brachii, triceps brachii, deltoid, and rotator cuff muscles.
5. Capillaries are small, thin-walled blood vessels that connect arteries and veins. They have a single layer of endothelial cells, which allows for the exchange of gases, nutrients, and waste products between the blood and the surrounding tissues. Oxygen (O2) and carbon dioxide (CO2) are stored and carried by hemoglobin, a protein found in red blood cells.
7F - Acids and Alkalis
1. An acid is a substance that donates hydrogen ions (H+) in solution, which lowers the pH of the solution.
2. An alkali is a substance that accepts hydrogen ions (H+) in solution, which raises the pH of the solution.
3. A neutral substance has a pH of 7 and is neither acidic nor alkaline.
4. Litmus is a pH indicator that turns red in the presence of an acid and blue in the presence of an alkali.
5. A variable is a factor that can be changed or manipulated in an experiment.
6. The reaction between an acid and an alkali is called a neutralization reaction.
7. Common word equations for neutralization reactions include:
- Hydrochloric acid + sodium hydroxide → sodium chloride + water
- Sulfuric acid + calcium hydroxide → calcium sulfate + water
- Nitric acid + potassium hydroxide → potassium nitrate + water
8. Reactants are the substances that react in a chemical reaction to produce products. Products are the substances that are produced by a chemical reaction.
I hoped this helped!