Bio Notes - Google Docs PDF
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These notes cover various biological topics, such as regulating body temperature, aerobic respiration, and the process of gas exchange in the human body. It also discusses blood and blood cells, as well as the different types of blood vessels.
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- Regulating body temperature:Low temperatures decrease cellular respiration in living tissues. All four reasons are parts of metabolism, a chemical process. Aerobic & Anaerobic Respiration Both types of respiration require energy (Glucose). Anaerobic respiration is differen...
- Regulating body temperature:Low temperatures decrease cellular respiration in living tissues. All four reasons are parts of metabolism, a chemical process. Aerobic & Anaerobic Respiration Both types of respiration require energy (Glucose). Anaerobic respiration is different from aerobic respiration because oxygen is not needed to break down glucose molecules. The amount of energy released from each glucose molecule is much smaller in anaerobic respiration. Anaerobic respiration in humans takes place in muscle cells during vigorous exercise. It produces lactic acid from glucose. A different form of anaerobic respiration takes place in yeast cells. Here the glucose is broken down into alcohol and carbon dioxide. Aerobic Respiration: Aerobic respiration occurs with oxygen and releases more energy but more slowly. - Occurs in the mitochondria - Requires oxygen - Produces carbon dioxide and water - Releases a lot of ATP energy - Up to 38 ATP molecules per molecule of glucose Anaerobic Respiration: Anaerobic respiration occurs without oxygen and releases less energy but more quickly. - Occurs in the cytoplasm - Does not require oxygen - Produces lactic acid - Releases very little ATP energy - Only 2 ATP molecules per molecule of glucose When there is a shortage of oxygen, anaerobic respiration takes place, so the oxidation of glucose is incomplete. This causes the production of lactic acid. Lactic acid accumulates at the tissues & muscles, causing burning sensations and cramps. Glucose Formula: C6 H1 2O6 + 6O2 -> 6CO2 + 6H2O Since O2 is present, the process of oxidization takesplace and produces a lot of energy. Gas Exchange The Roles of: 1. Goblet Cells:It secretes mucus that traps dust, dirt,and bacteria. 2. Mucus:Mucus traps microorganisms and other inhaledparticles. It helps protect the lining of the bronchus. 3. Ciliated Cells:These cells have hair-like projectionscalled cilia; it helps to move the mucus up and out of the airways. Adaptations of Alveolus: 1. Large surface area - More space for diffusion of gases to occur across. 2. Thin walls - Shorter distance for gases to diffuse across. 3. Good ventilation - Maintain diffusion gradients. 4. Good blood supply - Maintain a steep concentration gradient. Blood & Blood Cells Components of Blood - RBC (Red Blood Cell) - Erythrocytes - WBC (White Blood Cell) - Leukocytes - Plasma - Platelets Red Blood Cells: Fun Facts: - Contains Hemoglobin - Hemoglobin is a protein containing iron that facilitates the transport of oxygen in red blood cells. - Combines with oxygen to form oxyhemoglobin - Carries oxygen through cellular respiration Adaptations: - It doesn’t have a nucleus - Shaped like a biconcave disk - Large surface area White Blood Cells: Function: - < 1% of all the blood in the body - It is an essential part of our immune system - It helps defend against infections. - Has a neucleus Defenses: - Phagocytosis - Engulfs pathogens - Antibodies - Binds onto pathogens - Helps destroy them - Antitoxins - Neutralises any toxins Adaptations: - Irregular Shape - they can change shape to squeeze out of blood vessels and get to the site of infection. Platelets: Fun Facts: - Floats about in the blood - Blood clotting prevents cuts Plasma: Fun Facts: - Makes blood watery so it can flow - Carries everything - Glucose - Amino Acids - Hormones - Proteins - Wastes products - Co2 - Urea Blood Vessels Before blood enters the capillaries from the arteries, it first goes through arterioles, a blood vessel formed from the branching of the artery. As the blood leaves the capillaries, it will first travel through venules before reaching the veins. Arteries: - Pumps blood - Blood is oxygenated - Except for Pulmonary arteries, which are deoxygenated - Pumps blood away from the heart - Thick, muscular walls - Narrow lumen - Absent valves Capillaries: Capillaries are the smallest blood vessels and are often found in networks to create a mesh of blood vessels. - Exchanges gases - Is both oxygenated and deoxygenated - Pumps blood both into and away from the heart - Thinnest walls - To speed up diffusion - They also have “leaky” walls - Allows blood plasma out of vessel, forming tissue fluid which surrounds cells. - Narrow lumen - Absent valves Veins: - Carries blood back to the heart - Blood is deoxygenated - Except for pulmonary veins, which are oxygenated - Carries blood into the heart - Thin walls - Large lumen - Blood pressure is low - Present valves - To prevent backflow Double Circulatory System Humans have a double circulatory system, which means the blood passes through the heart twice on each loop around the body. It travels from the heart to the lungs, to the heart, to the rest of the body before returning to the heart. - Pulmonary circulation is a portion of circulation responsible for carrying deoxygenated blood away from the heart to the lungs and then bringing oxygenated blood back to the heart. - Systemic circulation is another portion of circulation where the oxygenated blood i pumped from the heart to every organ and tissue in the body, and deoxygenated blood comes back again to the heart. Semilinar Valves: - Aortic semilunar valve - Pulmonary semilunar valve Artioventricular Valves: - Bicuspid - Tricuspid Valves a) Structures A to D A: Left Atrium B: Left Ventricle C: Right Atrium D: Right Ventricle b) Blood Vessels E and F E: Aorta F: Pulmonary Artery c) Diseased Arteries Name: Coronary arteries How they become diseased: They can become diseased through atherosclerosis, which happens when fatty deposits build up on the artery walls, narrowing them and reducing blood flow. Factors like high cholesterol, high blood pressure, smoking, and diabetes contribute to this disease. Homeostasis In biology, homeostasis is the state of steady internal physical and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits. Pulse/Heartbeat Procedure: 1. Sit down and relax to take a resting pulse. 2. Place your first two fingers on the in-side of your wrist. 3. Feel for a strong pulse and count the beats for 30 seconds. 4. Multiply by 2 to get beats per minute (BPM). 5. If you can’t feel a pulse on your wrist, try checking under your jaw. a. Be careful as this makes some people lightheaded. 6. If your pulse feels irregular, try measuring for 60 seconds instead. a. Irregular beats will be noticeable and out of rhythm. Mind Mupper Immune System The immune system is a defence system that stands against pathogens. They have physical barriers that stop pathogens from getting in, and chemical systems thay destroy pathogens in the body. Physical Barriers: 1. Skin a. Secretes oils/antimicrobial substances 2. Nose a. Lots of tiny hairs i. Mucus (Traps the pathogens) 3. Mouth a. The pathogens go to the Trachea i. They have cilia, which trap the pathogens at the back of the throat. 4. Oesophagus a. Hydrochloric Acid - pH 2 Immune System: 1. White blood cells a. Phagocytosis - Engulfing or consuming particles and pathogens i. Tracking ii. Binding b. Antitoxins i. Cleans and counteracts the pathogens c. Antibodies i. Acts as a signal, and targets antigens 1. Any substance that causes the body to make an immune response against that substance ii. Made of small proteins Pathogens: Pathogens are foreign objects which are not supposed to be in our body/bloodstream. Bacteria, viruses, etc. Vaccines: Vaccines contains dead or weakened pathogens or pieces of them. The immune system recognizes the pathogen as foreign. The body produces antibodies to fight the pathogens. Memory cells are created to remember how to fight the pathogen. If the body encounters the real pathogen later, it can quickly fight it off.
