B2 Flashcards
What is the organisation of living organisms?
1.) Cell
2.) Tissue
3.) Organs
4.) Organ systems
5.) Organisms
What is a tissue?
A group of cells with similar structures and functions
What is an organ?
Group of tissues working together to perform a specific function
What is amylase?
An enzyme produces in the SALIVARY GLANDS and PANCREAS that breaks down CARBOHYDRATES into simple sugars
What is the aorta?
The main artery that takes OXYGENATED blood away from the heart
What is an artery?
Blood vessel that carries blood at HIGH PRESSURE away from the heart
What is a benign tumour?
An abnormal cell growth that stays where it is in the body and doesn’t invade other areas
What is bile?
A substance made in the LIVER and STORED in the gallbladder which is used to neutralise stomach acid in the intestine and emulsify fats
What is coronary heart disease?
A disease caused by the buildup of fatty deposits inside the coronary artery- reduces blood flow to the heart tissue
What are enzymes?
Biological catalysts that increase the rate of reactions in living organisms
What is lipase?
An enzyme that is produced the in PANCREAS that breaks lipids down into FATTY ACIDS and GLYCEROL
What is the ‘lock and key’ theory?
The theory that substrates have to be the correct shape to fit the active site of an enzyme
What is a malignant tumour?
Abnormal cell growth that can travel and invade other parts of the body via the blood
What is metabolism?
All of the chemical reaction occurring within an organism
What is palisade mesophyll?
A tissue found in plant leaves that is specialised to carry out photosynthesis
What is the pulmonary artery?
The main artery that takes deoxygenated blood away from the heart to the lungs
What is the rate of reactions?
The speed at which reactants are converted into products
What is the spongy mesophyll?
A tissue found in plant leaves that is specialised for gas exchange
What are statins?
Class of drugs that are used to reduce blood cholesterol level which slows down the rate of any fatty material deposit
What is a stent?
A tube that can be surgically implanted into blood vessels to keep them open
How does oxygen enter the blood?
Via the alveoli. Then, it’s transported to the heart through the pulmonary vein
When do enzymes work best?
At the optimum pH and temperature
Is bile alkaline or acidic?
Alkaline
How are alveoli adapted for gas exchange?
Large surface area
Thin
Moist
Where is amylase produced?
Pancreas, salivary glands and small intestine
Where is protease created?
Small intestine, pancreas, stomach
Where are lipids produced?
Small intestine, pancreas
What is amylase broken down into?
The starch is broken down into glucose
What is protease broken into?
The protein is broken down into amino acids
What is lipase broken down into?
Lipids are broken down into fatty acids and glycerol
Why is the food test for starch and what is the positive result?
Iodine- it will turn blue black
What is the food test for sugars and what is the positive result?
The Benedict reagent- it will turn green/yellow/orange/brick red depending on how much is in there
What is the food test for protein and what are the positive results?
The Biuret test- it’ll turn purple
What is the food test for fats/ lipids and what is the positive result?
Ethanol emulsion- a white emulsion will appear
What factors affect the rate of enzyme based reactions?
Temperature, pH, enzyme concentration, substrate concentration, surface area, pressure
What does it mean for an enzyme to denature?
When the temperature and pH goes beyond the enzymes optimum, the active site changes and the enzyme no longer works
What is transpiration?
The movement of water from the roots to the leaves through the xylem and then the loss of water by evaporation
What are the four factors that affect transpiration?
More light (stomata is open so water is lost)
Higher temperature (water evaporates quicker)
More wind (the wind blows the water out)
Lower humidity (air movement- the more there is, the higher the concentration gradient is)
What are the xylem and phloem used for?
Xylem- transports water via transpiration
Phloem- transportation of sugars via translocation
What is the use of the palisade layer?
Top layer of the leaf, contains chloroplasts for photosynthesis
What is the function of spongy mesophyll?
Facilitate diffusion of gases- loosely packed cells or tissues
What are the uses of the lower epidermis, stomata and guard cells?
Lower epidermis- contains guard cells and stomata
Guard cells and stomata- gas exchange
Meristem tissues- where are they, what do they contain and what occurs in them?
Where cell division occurs
On the roots and the shoot tips
Contains stem cells
