Digestive system Flashcards
Whats the role of the digestive system?
Break down food for energy, 4 major processes.
Ingestion: food enters through mouth
Digestion: Breakdown food into smaller components (Mechanical & Chemical)
Absorption: Nutrients are absorbed into bloodstream so it can be delivered to all cells in body
Egestion: Removal of waste production
What are the types of digestion
Mechanical and Chemical
Mechanical digestion
Physical breakdown of chunks of food into smaller pieces. Happens mainly mouth and stomach.
Chemical digestion
Chemical breakdown of large complex food molecules into smaller simple nutrient molecules that can be absorbed by the blood. Begins in mouth and stomach occurs in SI
Whats an enzyme?
Proteins which act as biological catalyst. Regulate/increase the rate of chemical reactions (like metabolism) within the body.
Basically makes reactions faster
Why can enzymes be used over and over again?
Enzymes do not get used up or altered permanently so they can be used again and again
What does enzymes do to activation energy?
Decrease activation energy of a reaction, this is energy needed to start a reaction
what is a substrate?
molecule that is getting broken down or built up.
Whats an active site
Enzymes have active sites, an area on an enzyme which has a special shape so that only a specific substrate will fit.
every substrate needs its own enzyme in the body
How do enzymes work?
- Subtrate and enzyme need to be in same area of body
- Subsrate fits into active site of enzyme (if same shape)
- Catalysis occurs (substrate broken down/built up)
- Products released from active site
- Enzyme grabs new substrate and repeats process
What is organic compounds
Need to be broken down before being absorbed into bloodstream. Eg Carbohydrate, protein, fat
What is Inorganic compounds?
Can be absorbed directly into bloodstream. Eg Vitamins, minerals, water
Whats a protein, why do we need it?
Composed of long chain of aminoacids, found in meat, fish, legume.
they are the building blocks for muscle
Whats a carbohydrate, why do we need it?
Composed of hydrogen, carbon, oxygen in fixed ratio. Can be simple/complex. Found in sugars, starches, bread, fruit, monosaccarides.
Main source of energy
Whats a fat/lipid why do we need it?
Can be saturated (animals/fats/butter) Unsaturated (oils)
Main component of cell membranes and long term energy storage, insulates and protects
How is glucose made? (carbohydrate)
starts from polysaccharide starch glycogen, enzyme amylase breaks it down into maltose (disacc), maltase breaks it down into Glucose (monosacc)
How is glucose + fructose made? (carbohydrate)
Starts from sucrose (disacc), enzyme sucrose breaks it down into glucose + fructose (monosacc)
How is glucose + galactose made? (carbohydrate)
Starts from lactose (disacc), enzyme lactase breaks it down into glucose + galactose (monosacc)
Whats the 3 levels of a protein?
Polypeptide: A long sequence of amino acids
Dipeptide: 2 amino acids
Amino acid: one protein unit, 20 in total humans need.