Animal Systems Questions PDF

Cellular Respiration - Photosynthesis: carbon dioxide + water + solar energy = glucose + oxygen + water ATP - Adenosine triphosphate - Consists of 3 phosphate groups, a ribose sugar and an adenine molecule (nitrogen base – purine) - A form of energy that can be used...

Cellular Respiration - Photosynthesis: carbon dioxide + water + solar energy = glucose + oxygen + water ATP - Adenosine triphosphate - Consists of 3 phosphate groups, a ribose sugar and an adenine molecule (nitrogen base – purine) - A form of energy that can be used by all types of cells - created through the process of cellular respiration Aerobic cellular respiration - produces large amounts of ATP (energy) glucose + oxygen carbon dioxide + water + 36 ATP molecules - The process occurs in several stages - The first stage is glycolysis and occurs within the cytosol (cytoplasm) - This process does require oxygen - Glucose splits into two pyruvic acids (pyruvates) glucose 2 pyruvates - The next stage occurs within the mitochondria 2 pyruvates + oxygen carbon dioxide + ATP - lots of folding in inner membrane to increase surface area and space for aerobic cellular respiration - cells that require more energy (ATP) have more mitochondria (example - muscle cells) Anaerobic respiration Ethanol fermentation glucose ethanol + carbon dioxide + 2ATP 🞆 occurs within the cytosol 🞆 occurs in single celled organisms such as yeast and bacteria 🞆 can be used in the production of breads, wine, beer and soy products -  Digestion and Essential Nutrients - The digestive system is responsible for the breakdown of large, complex organic materials into smaller components that are utilized by the tissues of the body. Every organ system depends on the digestive system for nutrients. - There are four components of digestion: - 1. ingestion— the taking in of nutrients - 2. digestion— the breakdown of complex organic molecules into smaller components by enzymes - 3. absorption— transport of digested nutrients to the tissues of the body - 4. egestion—the removal of waste food materials from the body Six essential nutrients to keep healthy 1. Carbohydrates 2. Proteins 3. Lipids 4. Liquids 5. Water 6. Vitamins 7. Minerals Proteins Proteins are the most complex of all nutrients. They are made up of long chains of smaller molecules called amino acids When you eat proteins, your body separates the proteins into individual amino acids so they can be rearranged and used as building blocks for human proteins protein can also be used to provide energy, and excess protein can be converted into high-energy storage molecules Carbohydrates - Carbohydrates are the main source of energy for the human body. - Carbohydrate molecules are made up of carbon, hydrogen, and oxygen. There are three main types of carbohydrates: monosaccharides - simple sugars, ring-shaped structures consisting of a single sugar molecule. (glucose and fructose) disaccharides - made up of two simple sugars joined together  (lactose and sucrose) polysaccharides - complex carbohydrates, may consist of hundreds of joined simple sugars. (starch, cellulose, glycogen) Plants store carbohydrates in the form of starch (in the roots, stems, leaves, and seeds) Animals store carbohydrates in the form of glycogen (in the liver and muscle tissues). If the maximum amount of glycogen is stored, excess carbohydrates can be converted to lipids and stored as body fat. When energy is needed, glycogen is converted back into usable glucose. Cellulose is used in plant cell walls to give the plant structure. Humans cannot digest cellulose, but it provides fibre, which is an important part of a healthy diet. Fats and Lipids - Lipids provide a concentrated source of chemical energy for the body. - They help in the absorption of vitamins, are a main component of cell membranes, and serve as insulation for the body. - Fats and oils are two familiar types of lipids. - Fats and oils are made up of three fatty acids bonded to a glycerol molecule, which make up a triglyceride. Vitamins - A vitamin is a compound that an organism needs as a nutrient only in small amounts. - Vitamins are classified as either fat soluble (will dissolve in fats) or water soluble (will dissolve in water). - Vitamins A, D, E, and K are fat soluble vitamins - Vitamins B and C are water soluble vitamins Minerals - Minerals are naturally occurring elements that the body uses to carry out metabolic processes and to build or repair tissues. - calcium and phosphorus - critical in the formation of bone. - sodium - nerve impulse transmission and muscle contraction. - iron – a key component of the blood protein hemoglobin. - Other minerals, such as fluorine, zinc, and copper, are present in our bodies in trace amounts. Digestion Path Mouth - The digestive tract of adult humans stores and breaks down organic molecules into simpler components. - Physical digestion begins in the mouth, where food is chewed and formed into a bolus (the Greek word for ball) by the tongue. Saliva Saliva is important in digestion because it: contains amylase enzymes that initiate carbohydrate breakdown; lubricates the food passage; dissolves food particles; activates the taste buds. Tasting Food particles dissolved in solution penetrate the cells of the taste buds located on the tongue and cheeks. ↓ Different types of receptors respond to specific flavours. ↓ The taste buds are equipped with receptors that have a specific size and shape. ↓ Nerve cells for taste are stimulated when receptor sites are filled by chemical compounds with a complementary shape The teeth The teeth are important structures for physical digestion. incisors are specialized for cutting canine are specialized for tearing premolars are specialized for grinding molars are found next to the premolars and are designed for crushing food. The Esophagus - The bolus of food stretches the walls of the esophagus, activating smooth muscles that set up waves of rhythmic contractions called peristalsis.  - Peristaltic contractions, which are involuntary, move food along the gastrointestinal tract. The Stomach - The stomach is the site of food storage and initial protein digestion. - The movement of food to and from the stomach is regulated by circular muscles called sphincters. - Contraction of the cardiac sphincter closes the opening to the stomach located near the heart, while its relaxation allows food to enter. - A second sphincter, the pyloric sphincter, regulates the movement of foods and stomach acids to the small intestine. - J-shaped - Has numerous ridges called rugae that allow it to expand so that it can store about 1.5 L of food. - Millions of cells line the inner wall of the stomach, which secrete the various stomach fluids, called gastric fluids or gastric juice, that aid digestion. Gastric Fluids - Gastric fluid includes mucous, hydrochloric acid (HCl), pepsinogens, and other substances. - Mucous provides a protective coating. - Hydrochloric acid keeps the pH of the stomach between 2.0 and 3.0 (but may approach 1.0). The low pH kills many harmful substances that are ingested with food. - It also converts pepsinogen into its active form, pepsin, which is a protein-digesting enzyme. - Pepsin breaks the long amino acid chains in proteins into shorter chains, called polypeptides. Protein Digestion - A protein-digesting enzyme, called trypsinogen, is released from the pancreas. - Once trypsinogen reaches the small intestine, an enzyme called enterokinase converts the inactive trypsinogen into trypsin, which acts on the partially digested proteins. - Trypsin breaks down long- polypeptides into shorter-chain peptides. - A second group of enzymes, the erepsins, are released from the pancreas and small intestine. - They complete protein digestion by breaking the bonds between short-chain peptides, releasing individual amino acids. Carbohydrate Digestion - The pancreas also releases pancreatic amylase, which continue the digestion of carbohydrates begun in the mouth by salivary amylase. - The intermediate size carbohydrates are broken down into disaccharides  - The small intestine releases disaccharide enzymes, called disaccharidases, which complete the digestion of carbohydrates. - Lipid Digestion - The liver continually produces a fluid called bile which contains bile salts, that aid in fat digestion. - Bile is stored and concentrated in the gall bladder. - The bile salts emulsify, or break down, large fat globules into smaller droplets. This is physical breakdown since chemical bonds are not broken. - Lipases are enzymes released from the pancreas that break down lipids (fats). - There are two different types of lipid-digesting enzymes. Pancreatic lipase, the most common, breaks down fats into fatty acids and glycerol. - Phospholipase acts on phospholipids. -