YEAR 9 Enzymes, Microscopy And Prefixes Flashcards
What is the purpose of enzymes
Enzymes catalyse specific reactions in living organisms due to the shape of their active site. Also, the activity of enzymes is affected by changes in temperature, pH and substrate concentration.
Describe the meaning behind the lock and key method
The lock and key theory is a simplified model to demonstrate enzyme action, as they catalyse different reactions depending on the shape of their active site.
Describe the purpose of digestive enzymes
Digestive enzymes sped up the conversion of large insoluble molecules (food) into small solvable molecules than can be absorbed into the blood stream easier.
Define the term denatured
When large changes in temperature or pH can stop the enzyme of working, and this is when an enzyme becomes denatured. When enzymes denature the substrate can no longer fit into the active site, making a chemical reaction much slower.
Describe enzymes such as amylase
Made in the salivary glands, pancreas, small intestines, and breaks down carbohydrates into simple sugars (e.g. amylase breaks down starch to glucose)
Describe proteases
Made in the stomach, pancreas, and it breaks down protein into amino acids.
Describe lipases
Made in the pancreas (but works in the small intestine) and breaks down lipids (fats) into fatty acids or glycerol.
Why are digestive enzymes useful for the human body?
The products of digestion are used to build new carbohydrates, lipids and proteins. Some glucose is used for respiration too.
Describe the process of calorimetry
The energy in food can be calculated by how much it heats up water when it burns in a calorimeter. The water must be moving so that the temperature is equal throughout, and the lid on so that no heat can escape in order to get the most accurate reading.
State the equation for magnification
Magnification = the size of the image / the real size of the object
Describe the radiation used in both types of microscopes
Light microscope - light rays
Electron microscope - electron beams
Describe the max. magnification in both microscopes
Light microscopes - 1500 times
Electron microscopes- 2000000 times
Describe the resolution in both microscopes
Light - 200nm
Electron - 0.2nm
Describe the size of both microscopes
Light - small
Electron - very large
Describe the cost of both microscopes
Light - £100
Electron - £100,000 - £1000000+
