topic 2 Flashcards
What is the job of muscular tissue, glandular tissue and epithelial tissue?
Muscular-contracts to move whatever it’s attached to, and moves stomach wall to churn food. Glandular-makes and secrets chemicals e.g. enzymes and hormones, and makes digestive jucies to digest food. Epithelial-covers some parts of body e.g. inside of gut, and covers outside and inside of stomach.
What is a tissue?
group of similar cells that work together to carry out a particular function.
What is an organ?
Group of different tissues that work toghther to perform a certain function.
What is an organ system?
group of organs working together to perform a particular function.
What is an enzyme?
A biological catalyst. Enzymes reduce the need for high temperatures and we only have enzymes up to speed the useful chemical reactions in the body. A catalys is a substance which increases the speed of a reaction without being changed or used up in the reaction. Enzymes are all large proteins and all protiens are made up of chains of amino acids. These chains are folded into unique shapes, which enzymes need to do their jobs.
What is an active site and substrate?
Every enzyme has an active site with a unique shape that fits onto the substrate involved in a reaction. Enzymes useually only catalyse 1 specific reaction. Becuase for enzyme to work, substrate has to fit into its active site. If substrate doesn’t match enzyme’s active site, then the reaction won’t be catalysed.
What is the ‘lock and key model’?
See revison guide.
How can changing the temperature have an effect on the enzyme?
Higher temperature increases rate at first. But if gets too hot, some of bonds holding enzyme together break. Changes the shape of enzyme’s active site, so substrate won’t fit any more. Enzyme is said to be denatured. All enzyms have an optimum temperature that they work best at.
How can changing the pH have an effect on the enzyme?
If too high or low, pH interferes with bonds holding enzyme together. This changes shape of active site and denatures the enzyme. All enzymes have a optimun pH that they work best at. It’d often neutral pH 7. E.g. pepsin is an enzyme used to break down proteins in stomach. It works best at pH2, which means it is more suited to acidic conditions there.
What is amylase used for?
Breakdown starch to maltose. Easy to detect starch using iodine solution-if starch present iodine solution will change from browny-orange ot blue-black.
What are the first steps to test for starch?
Put a drop of iodine solution into every well of spotting tile. Place bundsen burner on a heat-proof mat, a tripod and gauze over bundsen burner. Put beaker of water ontop of tripod and heat water until its 35 Celcius (use thermometer to measure temperature). Try to keep temperature of water constant throughout experiment.
What do you do after you have measured the temperature of the water?
Use a syring to add 1cm3 of amylase solution and 1cm3 of a buffer solution with a pH of 5 to a boiling tube. Using test tube holdrs, put tube into beaker of water and wait for 5 minuites. Next use a differenet syringe to add 5cm3 of a starch solution to boiling tube. Immediatly mix contents of boiling tube abd start stop clock.
What do you do with continuous sampling?
Record how long takes foramylase to break down all of starch. To do this, use a dropping pipette to take a fresh sample from boiling tube every 30 seconds and put a drop into a well. When iodine solution remains browny-orange, starch is no longer present.
Why do we repeat the experiment with buffer solutions of different pH values?
To see how pH affects time taken for starch to be broken down. Remeber to control variables each time. (e.g. concentration and volume of amylase solution) to make it a fair test.
Does rate of reaction change over time?
Yes
What is the formula for rate of reaction?
rate=1000/time. Units aer in s-1 since rate is given per unit.
What does an experiment and calculations do?
Experiment: meaures how much something changes over time.
Calculation: can calculate rate of reaction by dividing amount that it has changed by time taken.
Why does digestion need to break dow food to smaller molecules?
so they can pass through walls of digestibe system easily, alowing them to be aborbed into blood stream.
What is the examle of carbohydrases convert carboyhdrates into simple sugars?
Amylase is example of carbohydrase-breaks down starch. see revision guide. Amylse found in slaivaryglands, pancreas and small intestine.
What is the example of proteases convert proteins into amino acids?
see revision guide
proteins are found in stomach (called papsin there)
pancreas
small intestine.
What is the example of lipase convert lipids into glycerol and fatty acids?
See revision guide. Lipases found in pancreas and small intestine.
What are the products of digestin used as?
new carbohydrates, proteins and lipids. Some of glucose (carbohydrate) that is used in respiration.
What is the example of bile to emulsifie fat?
Produced in liver, stored in gall bladder before released into small intenstine. Hydrochloric acid in stomach makes ph too acidic for enzymes in small intestine to work properly. Bile is alkalint-neutralises acid and makes conditions alkaline. Enzyme in small intestine works best in these alkaline conditions. It emulsifies fats. It breaks down fat into tiny droplets. Gives much bigger surface area of fat for enzyme lipase to work on-makes digestion faster.
What happens in the salivary glands?
produce amylase enzyme in saliva.
What happens in the liver?
Bile is produces.
What happens in the stomach?
pummels food with its muscular walls, produces protease enzyme, pepsin, produces hydrochloric acid for 2 reasons, to kill bacteria and to give the right pH for the protease enzyme to work. pH2-acidic
What happens in the gall bladder?
Bile is stored before it’s releaed into small intestine.
What happens in pancreas?
Produces protease, amylase and lipase enzymes. Releases these into small intestine.
What happens in the large intestine?
Excess water is absorbed.
What happens in small intestine?
Produces protease, amylase and lipase enzymes to complete digestion. Also where digested food is absorbed out of digestive system into blood.
What do you do to prepare a food test?
get a piece of food and break it up using pestle and mortar, transfer ground up food to beaker, add some distilled water, give mixture a good stir with a glass tod to dissolve some of foodm filter solution using funnel lined with filter papaer to get rid of solid bits of food.
What do you do for the Benedict’s test to test for reduced sugars?
2 types of sugars, reducing and non-reducing. First prepare food sample and transfer 5cm3 to test tube, prepare water bath so that it’s set to 75 Celcius, add some Benedict’s soution to test tube (about 10 drops) using pipette. Place test tube in water bath using test tube holder and leave it ther for 5 minuites. Make sure tube is pointing away from you, If food contains reducing sugar, solution in test tube will change from normal blue to green yellow or brick-red-depends on how much sugar is in food.
What is involved in iodine soluition to test for starch?
Make food sample and transfer 5cm3 of sample to test tube, add a few drops of iodine solution and gently shake the tube to mix contents. If sample contains starch, colour of solution will change from browny-orange to blakck or blue-black.
What is involved for the biuret test to test for proteins?
Prepare sample of food transfer 2cm3 of sample to test tube, add 2cm3 of biuret solution to sample and mix contents of tube by gently shaking it. If food sample contains protein, solution will change from blue to pink or purple. If no protein is present, solution stay blue.
What is involved to use Sudan III to test for lipids?
prepare sample of food you’re testing (but don’t need to filter it) .Transfer 5cm3 into test tube, use pipette to add 3 drops of Sudan III stain solution ot test tube and gently shake tube. Sudan III stain solution stains lipids. If smaple contains lipids, mixture will seperate out into 2 layers. Top layer will be bright red. If no lipids present, no seperate red layer will form at top layer of liquid.
What is the stucture of the lungs?
Thorax is top part of body, is seperated from lower part of body by diaphragm. Lungs are bink pink sponges and are protected by the ribcage. They’re surrounded by pleural membranes.
What happensafter you breath in air?
goes through trachea. Splits into 2 tubes called bronchi (each one is bronchus), 1 going to each lung. Bronchi split into progressively smaller tubes called bronchioles. Bronchioles finally end at small bags called alveoli where gas exchange takes place.
how is gas exchanged
blood passing next ot alveoli just returned to lungs from rest of body, so contains lots of co2 and very little oxygen. Oxygen diffuses out of alveolus (high concentration) into blood (low concentration) into alveolus (low concentration) to be breathed out.
What happens in gas exchange?
When blood reaches body cells oxygen is released from red blood cells (high concentration) and diffuses into body cells (low concentration). At same time co2 diffuses out of body cells (high concentration) into blood (low concentration). Then carried back to lungs.
How do you calculate breathing rate in breaths per minuite?
breaths/minuites.
What is the circulatory sytem made of?
Blood vessels, heart, blood.
What are the stages of the circulatory system?
First one: Right ventricle pumpsc deoxygenated blood to lungs to take in oxygen. Blood returns to heart.
Second one:Left ventricle pumps oxygenated blood around all other organs of body. Blood gives up its oxygen at body cells and deoxygenated blood returns to heart to be pumped out to lungs again.
What tissue are the walls of heart mainly made of?
Muscle tissue
What are valves used for?
To prevent the backflow of blood.
What happesn when blood flows into the 2 atria form the vena carva and pulmary vein?
The atria contract, pushing blood into ventricles, ventricles contract, forcing blood into pulmary artery and aorta and out of heart. Blood then flows to organs through arteries, and returns through veins. Atria fill again and the cycle begins again.
Doest the heart have its own supply of oxygenated blood?
Yes.
What are coronary arteries?
branch off aorta and surround heart, making sure it gets all oxygenated blood it needs.
what is a pacemaker?
Your resting heart is controlled by a group of cells in right atrium wall that act as a pacemaker. These cells produce a small electric impulse which spreads to surrounding muscle cells, causing them to contract.
What is an artificial pacemaker?
An artificial pacemaker is often used to control heartbeat if the natural pacemaker cells don’t work properly (e.g. if the patient has an irregular heartbeat). It’s a little device that’s implanted under the skin and has a wire going to the heart. It produces and electric current to keep the heart beating regularly.
what are arteries, capillaries and veins?
Arteries: carry blood away from heart.
Capillaries: involved in exchange of materials at tissue
Veins: carry blood to heart
What are the properties of arteries?
Heart pumps blood out at high pressure so artery walls are thick compared to size of hole in middle (lumen). They contain thick layers of muscle to make them strong and elastic fibres to allow them to stretch and spring back.
