2-Organisation Flashcards
What is the food test for sugars?
*Prepare food sample and transfer 5cm^3 to a test tube
*prepare a waterbath set at 75^0c
*Add benedicts solution to test tube using pipette
*leave in water bath for about 5 minutes
*if positive result, will turn green, yellow or brick red, depending on amount present
What is the food test for starch?
*Prepare food sample and transfer 5cm^3 of sample to test tube
*Add iodine solution and gently shake
*If positive result, change from brown-orange to black or blue-black
What is the food test for protein?
*Prepare food sample and transfer 2cm^3 of sample to text tube
*add 2cm^3 biuret solution and gently shake
*If positive, change from blue to purple
What is the food test for Lipids?
*Prepare sample and transfer 5cm^3 to a test tube
*add 3 drops of ethanol and shake vigarously
*let contents settle
*If positive, solution appears cloudy
What is a cell?
Cells are the basic building blocks of all living organisms
What is a tissue?
A tissue is a group of cells with a similar and function
What is an organ?
Organs are groups of tissues performing specific functions
What is an organism?
• Organs organised into organ systems
• Working together to form an organism
What is the digestive system?
• An organ system in which several organs work together to digest and absorb food
What is the ‘lock and key’ theory?
• Enzymes and their substrates binding together perfectly like lock and key
Where is amalyse produced?
The pancreas
What is the role of amalyse?
Digest starch into smaller molecules
Where is protease produced?
• Stomach
• Pancreas
• Small intestine
What is the role of protease?
• Breaks down proteins
• Into amino acids
Where is lipase produced?
• Pancreas
• Stomach
• Mouth
What is the role of lipase?
• Breaks down lipids
• Into fatty acids and glycerol
What is the role of digestive enzymes?
• Convert food into small soluble molecules
• That can be absorbed into the blood stream
What is the role of carbohydrases?
• Break down carbohydrates to simple sugars
What is amalyse?
• A carbohydrase
• Breaks down starch
What are the products of digestion used for?
• To build new carbohydrates, lipids and proteins
• Some glucose used in respiration
Where is bile made and stored?
• Made in the liver
• Stored in the gall bladder
What is the role of bile?
• Alkaline to neutralise hydrochloric acid in the stomach
• Emulsifies fat to form small droplets which increase SA
Why is bile useful?
• Alkaline conditions and large surface area increase rate of fat broken down by lipase
What is the heart?
• Organ that pumps blood around the body in a double circulatory system
• Made of cardiac muscle
What is the role of the right ventricle?
Pumps blood to the lungs where gas exchange takes place.
What is the role of the left vernticle?
- Pumps blood around the rest of the body
- Thicker to withstand higher pressures
What is the role of the aorta?
Pump oxygenated blood to the rest of the body
What is the role of the Vena cava?
Receives oxygenated blood from the body
What is the role of the Pulmonary artery?
Where deoxygenated blood is pumped to the lungs.
What is the role of the pulmonary vein?
Where oxygenated blood enters the heart from the lungs
What is the coronary artery?
Arteries that carry blood back to the heart
What is the role of the trachea?
A tube for air to pass into the lungs
What is one adaption of the trachea?
- Contains rings of cartilage
- To prevent the lungs from collapsing as we inhale
What are the bronchi?
*The trachea split into two smaller branches
* One of which going into each lung
What are the bronchioles?
The bronchi split into even smaller branches
What are alveoli?
- Small sacks at the end of the bronchioles
- Where gas exchange takes place
How do the alveoli carry out gas exchange?
- Release oxygen from red blood cells which diffuses into the body cells
- At the same time, carbon dioxide diffuses out of the body cells and carried back to the lungs
How is alveoli adapted for maximum rate of gas exchage?
- Steep concentration gradient of oxygen rich blood from the lungs to low concentration of oxygenated blood
- Thin walls for shorter diffusion pathway
- Large surface ares to increase rate of diffusion
- As there’s a larger surface for the particles to diffuse from
Describe how the heart pumps blood to the lungs and rest of the body.
- enters heart via vena cava
- Passes through right atrium and is pumped to right ventricle
- Exits heart through pulmonary artery and travels to the lungs
- Becomes oxygenated in the lungs
- Re-enters heart via pulmonary vien
- Passes through left atrium and left venticle
- Oxygenated blood pumped from heart to the rest of the body
What do arteries do?
Carry blood away from the heart
What viens do?
Carry blood to the heart
What do capillaries do?
Involved in exchange of gases at the tissues
Describe arteries.
*Contain thick layers of muscle
* To withstand high pressures
* Smaller lumen
Describe viens.
- Contain thin layers of muscle
- As they dont need to withstand high pressures
- Larger lumen to increase blood flow
- Contain valves to prevent backflow of blood
Describe Capillaries.
- Supply food and oxygen and take away C02
- One cell thick to decrease diffusion disance
- Carry blood very close to cells to exchange substances with them
What is the function of blood plasma?
- To carry substances around the body such as;
-glucose and amino acids from digestion
-Carbon dioxide
-Urea
-Hormones
-Protiens
What is the function of platelets?
- To help clot the blood
What is the function of white blood cells?
- Engulf and destroy pathogens
- Produce antibodies to attack microorganisms
- Produce antitoxins to neutralise toxins
What is the function of red blood cells?
- Carry oxygen around the body
- Biconcave disc to increase surface area
- No nucleus to carry more oxygen
- Contain haemoglobin that bind to oxygen to form oxyhaemoglobin then release oxygen at cells
What is coronary heart disease?
- Fatty materials build up inside coronary arteries
- Causing them to narrow
- Reducing blood flow
- So less oxygen for the heart muscle
What are stents for?
Used to keep coronary arteries open
What are statins used for?
To reduce blood cholesterol and slow down rate of fatty material deposits
What are the consequences of leaky valves?
- Causes breathlessness
- Leads to death if untreated
- Can be replaced with mechanical valves or biological valves
What are the benefits of mechanical valves?
They last a very long time
What are the drawbacks of mechanical valves?
Need to take drugs for the rest of patients life to prevent blood from clotting around it
What are the benefits of biological valve replacements?
- Work extremely well
- Dont need to take medication
What are the drawbacks of biological valve replacements?
Only last 12-15 years
What is the definition of health?
State of physical and mental well-being
What causes ill-health?
- Disease
- Diet
- Stress
- Life situations
How does immune system defects interact with other disease?
Makes an individual more likely to suffer from infectious diseases
How does a virus interact with other diseases?
Viruses living in cells can be the trigger for cancers
How do pathogens react with other diseases?
Immune reactions initially caused by pathogens can trigger allergies such as rashes and asthma
How does severe physical ill health interact with other diseases?
Can lead to depression and other mental illness
What is the role of the xylem?
transports water and minerals up the plant, through the stem into the leaves as part of the transpiration stream
Describe the structure of the xylem.
- No end walls
- Made up of dead cells
- Walls thickened with lignin
What is the role of the phloem?
transports food substances and products of photosynthesis around the plant (up and down) e.g growing plants of the plant, storage organs (bulbs) via translocation
Describe the structure of the phloem?
- sieve plates/pores in end walls
- living cells
- contains cytoplasm
What is transpiration?
The movement of water out of the leaves via the xylem
What is translocation?
The movement of sugar produced in photosynthesis around the plant via the phloem
What are the factors affecting transpiration?
- Temperature
- Humidity (decrease)
- Air movement e.g wind
- Light intensity
