Unit 3: Body Systems, The Digestive System Flashcards
What is the small intestine
Where most chemical digestion occurs.
-Proteins, carbs, lipids are fully digested.
-Absorption also begins
Parts of the small intestine
- Duodenum: contains pancreatic juices and bile that allow most of digestion to occur
- jejunum: Remaining breakdown of carbs and proteins
3.Ileum: Absorption of nutrients
Hierarchy of living things
-cells:simplest unit of life
-tissues: group of specialized cells that carry out functions
-organs: Specialized tissues that group to carry out a function for the body
-organ system:Group of organs that carry a function
-organism: all of the tings bellow build an organism
Metabolic processes
- Ingestion: take in nutrients in the form of food
- Digestion:Breaking down food to get nutrients needed
- Absorption: Taking in nutrients from digested food
- Egestion: Ridding the body of waste products that results from steps above
4 types of macromolecules
- Carbohydrates
2.Lipids
3.Proteins - Nucleic acids
Carbs (macromolecules)
-compounds made of carbon, hydrogen and oxygen atoms
-main energy source for your body
-divided into simple and complex carbs
Simple carbs
-includes sugars (glucose, fructose, galactose) like fruit, honey and milk
-Glucose is a type of sugar molecules which cells breakdown to extract their stored energy as their main fuel supply
-Cells also use carbon chains of simple sugars like raw material to manufacture other kinds of molecules
-glucose that your cells do not use immediately are incorporated into larger carbs or are used to make fast molecules (adapose tissue)
Complex carbs
-includes starches : whole grains, rice, potatoes
-Broken down into simple sugars/ carbs by your digestive system and absorbed into the blood and carried to the cells of the body
-excess blood sugar is converted into glycogen (stored in the liver, muscles and fat cells)
-glycogen is a chain of many glucose molecules .
-when the body needs energy it breaks down glycogen releasing glucose
Lipids (macromolecule)
-fats
-formed from fatty acids and glycerol
-store energy in the body and help the body absorb fat soluble vitamins
-cushion organs, insulate
3 types of fats
-saturated
-unsaturated
-trans
Saturated fats
-fats that only have single bonds between carbon atoms
-called saturated as each of these carbon atoms has a max number of hydrogen atoms
-ex, animal fats, lard, butter
-diets rich in saturated fats cause build up of fat deposits within the walls of blood vessels that reduce blood flow and cause heart disease
Unsaturated fats
-at least one double bond in a fatty acid chain
-ex, vegetables, fish, fruit, olive oil, avocado
-liquid at room temperature
Trans fats
-unsaturated fats that have been partially hydrogenated
-processed to accept more hydrogen atoms
-solid at room temperature
Proteins
-complex molecule constructed from amino acids
-20 amino acids
-proteins: form hair and muscles, long term nutrient storage, circulate in the blood, make antibodies, work with enzymes to control chemical reactions in a cell
-enzymes that are not consumed in a reaction but speed up chemical reactions
Amino acids
-8 essential amino acids, you can’t make form other molecules
- if you are missing one you can’t make protein properly
-ex, meat, milk eggs, cheese provide 8 aa
-people who are vegan need to get the aa from different sources
Vitamins
-organic nutrients (nutrients that contain carbon)
-in small amounts to regulate metabolic processes and perform chemical reactions
Water soluble vitamins
-vitamin b and c
-can’t be stored in the body, should be in the body everyday
Fat soluble vitamins
- vitamins a d e k
-small amounts can be stored in fatty tissues
Minerals
-inorganic nutrients that don’t contain carbon
-calcium, iron, copper, sodium, phosphorous, zinc
-you require a variety of minerals ex. Calcium to make bones and teeth
Water
- most important nutrient
-cells need water to complete its processes
-bodily chemical reaction take place in water
-water makes up bodily fluids and blood
-drink one litre a day
Large intestine parts
-contains the appendix and the colon
-colon absorbs water ad minerals, contains bacteria that breaks down nutrients
4 parts to the colon
-ascending colon
-transverse colon
-descending colon
-sigmoid colon
Rectum and anus
Rectum : stores fecal matter
-feces moves out of the anus as the anal sphincter relaxes
Mechanical and chemical digestion steps
- Mouth
2.stomach - Small intestine
- Large intestine
Mechanical and chemical digestion step 1
Mouth
-mechanical digestion occurs by chewing
-chemical digestion occurs when salivary gland prince saliva
-saliva contains amylase which chemically breaks down starch
-food is now a bonus (partially digested)
Mechanical and chemical digestion step 2
Stomach
-where bolus is stored
-protein digestion occurs
-gastric juices are secreted
3 types of gastric juices in the stomach
- HCL1 (hydrochloric acid): kills bacteria, kills viruses in undigested foods converts pepsinogen to pepsin by cleaving it
- Pepsin: protein digesting enzyme, breaks proteins into shorter polypeptides
3.Mucus: protects stomach lining form HCL and digestive enzymes
Mechanical and chemical digestion step 3
Small intestine
-most digestion occurs
-partially digested food is bathed in acid and pepsin enzymes
-pancreas secretes a pancreatic juice into SI that breaks down proteins, fats and carbs
-trypsinogen is released from the pancreas and converted to trypsin by enterokinase
Mechanical and chemical digestion step 4
Large intestine
-NO mechanical and chemical digestion
-Stores waste long enough for water, minerals and vitamins to be absorbed
-E. coli is present and makes vitamin k
Optimal factors for enzymes
Enzymes: are proteins that work to breakdown food into smaller substances
-Temperature: Should be at body temperature (36-38)
-Ph: depends on the part of the body ex, mouth is stomach
-if optimal factors are exceeded the enzymes looses its form (denatures)
-when optimal factors are not reached the enzyme remains inactive
Extracellular Digestion
Outside cells
Intercellular digestion
Within cells by a single celled organism
Chemical digestion
Uses enzymes to break chemical bonds within a food molecule ex, protein -> amino acid
Mechanical digestion
Breaking apart of food into smaller pieces
