A type of protease enzyme, it's best in acidic conditions (pH 2) like with hydrochloricacid in the stomach that breaks down proteins into aminoacids.
Mouth
Teeth chew the food
Salivaryglands secrete amylase enzyme
Stomach
Produces pepsin enzyme
Produces hydrochloric acid
Liver
Filters blood and breaks down poisonous substances by producing bile that neutralises HCI acids and emulsifies fats.
Pancreas
Produces protease, carbohydrase, and lipase enzymes
Small intestine
Breaks down food
Produce protease, carbohydrase, and lipase enzymes
Where digestion is completed and nutrients are absorbed
Large intestine
Absorbs excess water from digested food
Waste is moved to the rectum and exited through the anus
Mechanical digestion
Involves physicalbreakdown of food using teeth and muscles
Chemical Digestion
Enzymes help break down food
The mouth has saliva that contains amylase
The mouth ONLY digests starch.
The stomach only has pepsin.
The stomach only digests protein.
Oesophagus
carries food to the stomach through muscularcontractions called peristalsis
Adaptions of the small intestine
Has a very largesurfacearea covered in villi
rich-bloodsupply with short diffusion distance to bloodvessel
Lipase
A digestive enzyme that breaks down lipids into fattyacids, glycerol
Gallbladder
Stores excess bile and leads to the small intestine
Enzymes catalyse specific reactions to ensureprecision in biologicalprocesses.
Explain why starch has to be digested
Starch (molecules) are large/insoluble, so cannot be absorbed into the blood.
pH affects enzyme activity as some pH values denature enzymes, so substrate will no longer fit to the active site.
Enzymes
A protein and BIOLOGICAL CATALYSTS that speed up reactions and are produced by living organisms to regulate chemical reactions.
Structure of Enzymes
Enzymes are large PROTEINS composed of amino acid chains, which fold into UNIQUE SHAPES that are crucial for their function.
How Enzymes Work
Lock and Key Mechanism
Each enzyme has an ACTIVE SITE with a shape that fits substances known as SUBSTRATES.
Enzymes are SPECIFIC, so only one type of enzyme will fit one type of substrate
How Enzymes Work
The specificity of enzymes catalyse a particular reaction, ensuring precision in biological processes, but enzyme's active site changes slightly to secure the substrate.
Factors Affecting Enzyme Activity
Temperature
As you increase the temperature, the rate of enzyme-controlled reactions also increase up to a certain point, because the enzyme and substrates move around faster meaning there are MORE COLLISIONS per second with the rate is the fastest at the OPTIMUM TEMPERATURE.
Factors Affecting Enzyme Activity
Temperature
As the temperature increases past the optimum, the rate DECREASES, because the enzymes DENATURE causing the active site to change shape.
Factors Affecting Enzyme Activity
pH
All enzymes have an OPTIMUM pH that they work the best in and As the pH increases or decreases from the optimum, the rate of reaction DECREASES, because enzymes DENATURE causing the active site to change shape.
Most enzymes in the human body have an optimum pH of 7, but there's some with different ones.
"Lock and key theory" of enzyme action
enzyme joins to the substrate because the substrate fits the active site, so substrate is broken down into products and products are released.
CARBOHYDRASES break down carbohydrates into simple sugars.
PROTEASES convert proteins into amino acids.
LIPASES break down lipids into glycerol and fatty acids.
AMYLASE
A carbohydrase enzyme that breaks down carbohydrates / starch into maltose (a simple sugar), glucose, sucrose.