Vocabulary:

• Nutrition: The process by which an animal takes in nutrients and eventually uses them

• Compartmentalization: The sectioning off of areas and systems within an organism

• Glucose: Essential sugar that plants and animals use to extract chemical energy to synthesize ATP

• Essential nutrients: Nutrients required by cells that can only be obtained from dietary sources, cannot by synthesized by the body

  • Essential amino acids: the ones the body cannot synthesize, typically come from animal products

  • Essential fatty acids: Generally unsaturated, obtained through seeds, grains, and vegetables

  • Vitamins: Organic molecules required in the diet in tiny amounts, over 13 essential

    • Fat-soluble: Soluble in fat, stay in the body for longer and thus easier to over-consume, A D E and K

    • Water-soluble: Soluble in water, B 1 2 3 5 6 7 9 12 and C

  • Minerals: Inorganic molecules, also required in small amounts, typically salts. Examples are Fe, Ca Mg, F, K, P, S, Na, I

• Macronutrients: Required in large amounts

• Micronutrients: Needed only in small amounts

• Opportunistic feeder: Despite something being a carnivore/herbivore, if something is available it will go outside of its normal eating range

• Overnourishment: Obesity, too many calories with excess fat

• Undernourishment: Starvation, not enough calories, when the body breaks down its own tissue to survive

• Malnourishment: Enough calories are consumed, but a diet lacks one or more essential nutrients. This is the hardest to detect and understand

• Deficiency: Can cause deformity, disease, and death. Caused by malnutrition of various nutrients

• Mechanical digestion: Physically chewing food

• Chemical digestion: Using enzymes to hydrolyze food into more broken down forms, breaks polymers into monomers or smaller molecules, down into fatty acids, simple sugars, and amino acids

• Absorption: Absorption of nutrients

• Elimination: The process of getting rid of excess waste eaten after it is broken down and the nutrients are taken from it

• Pharynx: Part of both the digestive and respiratory system

• Esophageal sphincter: Flap, when relaxed good can go down, when closed (up far) air can go in and out of the lungs

• Peristalsis: The rhythmic movement of smooth muscles, this is the reason food can be swallowed upside down, happens due to many muscle contractions and relaxations involuntarily

• Villi: Folds within the intestines, increase surface area and are lined with epithelial cells

• Microvilli: line the epithelial cells of the villi, also ups surface area

• Mucosa: Inner lining of the intestines that secretes mucus, better allows for absorption

• Chylomicrons: Package non-water soluble fats into lipoproteins, they first enter a lacteal of a lymphatic system then into the veins of the circulatory system

• Liver: Absorbs toxins, adjusts nutrient contents, monitors blood content

• Gastrovascular cavity: Takes care of digestion and circulation for simpler organisms, known as an incomplete digestive system. They have only one opening, and organisms are smaller

• Complete digestive system: has two openings, many shapes, structures, and functions of various organs

• Crop: Stores food

• Gizzard: Grinds food

• Carnivore: Eat meat, have sharp teeth for tearing through food, have canines. They can expand their stomachs

• Herbivore: Eat plants, incisors are modified to bite off vegetation, better for grinding food. They have longer digestive systems that carnivores, and much larger cecums. This increased the processing of poor-protein foods, meaning they get more from what little is in plants. Most of the diet consists of cellulose

• Omnivores: Eat all kinds of food, generally unspecialized teeth

• Rumenate: Circulate food for long periods of time, use microorganisms to digest plant fibers, this occurs in the rumen

• Glycogen: Preferred form of energy storage, make from excess energy, a polymer of glucose, short-term as opposed to long term

• Fat: Long-term energy storage

• Glucagon: Allows for glycogen breakdown, produced by alpha cells in pancreas

• Insulin: Allows for the storage of glucose, rises with high carbohydrate and protein diets, produced by beta cells in the pancreas, suppresses appetite

• Hepatic portal vein: Senses levels of glucose, low levels is when glucagon levels rises which then increases blood sugar levels

• Ghrelin: The hormone that when secreted creates a feeling of hunger

• Leptin: Hormone produced by adipose tissue, suppresses appetite

An animal diet includes:

• Glucose

• Things that are used as building blocks

• Essential nutrients (amino acids, fatty acids, vitamins, and minerals)

Feeding mechanisms:

• Suspension feeders: Filter feeders, example being massive blue whales that filter feed on small crustaceans

• Substrate feeders: Eat what they live one, like a caterpillar eating the leaf its on

• Fluid feeders: Draw fluid from a host, which contains nutrients. These are often carriers of diseases, an example is an aphid or mosquito

• Bulk feeders: Eat a BUNCH at once, like a snake that eats once every 2 weeks, or even humans

Digestive system:

• Chemical digestion done by saliva excreted from glands, contains amylase that breaks down carbohydrates

• Mechanical digestion starts in the mouth with teeth that tear and grind food

• In the stomach there is no carbohydrate digestion, focus is on the proteins

• Mechanical digestion in the stomach crushes food

• The stomach is acidic, allowing the enzymes like pepsin to break down proteins

• The stomach also has esophageal sphincters

• Bile excreted from the liver helps emulsify fats, which makes the job of the enzymes easier

• The intestine uses peristaltic waves to move food

• Amino acids and sugars go directly into capillaries once broken down

• Things that cannot be digested, like fiber, move on to the large intestine, where they are stored before they are eliminated. Here, additional water is reabsorbed

• Vertebrates cannot digest cellulose, so bacteria is used in symbiosis

Diabetes:

• Homeostatic range is 70-110 mg of glucose in 100 mL of blood

• Mellitus:

  • Caused by insulin deficiency, or lower response from target cells

  • Insulin insensitivity

  • Cells can’t use glucose as efficiently, rely on fat more prominently

  • Instead of in cells, the glucose ends up in blood, which is too much for the kidneys to handle, leading to increased levels of glucose in urine

  • Type 2 diabetes

  • Heredity is a large factor

  • Can be caused by overnourishment

• Type 1

  • Autoimmune disorder

  • Can be caused by viral infection

  • Occurs when the immune system destroys pancreatic beta cells, halting the production of insulin

  • Appears in childhood

  • Treated with insulin injections

Enzymes in the digestive system break down nutrients, this area is acidic

Organisms can synthesize 20 amino acids, the rest are essential

Consequences of amino acid deficiency includes the halting of translation of proteins, resulting in an overall deficiency