bio test 2 Flashcards
what is diffusion
movement of particles from an area of high to low concentration.
what three main factors affects the rate of diffusion ?
larger concentration gradient…
higher temperature…
larger surface area…
…faster rate of diffusion
give examples of substances transported by diffusion in the lungs and kidney
lungs - oxygen diffuses into the blood from the lungs and carbon dioxide diffuses into the lungs from the blood, both down their concentration gradient.
kidney - urea diffuses from cells into the blood plasma so it can be discarded in urine.
How are single-celled organisms adapted for diffusion?
They have a large surface area to volume ratio - maximizes the rate of diffusion of molecules to meet the organism’s needs.
How is surface area to volume calculated ?
surface area
NUMBER OF SIDES X (SIDES LENGTH X SIDES WIDTH)
How is volume calculated ?
volume
Length x Width x Depth
what 4 factors increases the effectiveness of gas exchange surface?
- large surface area
- thin membrane (short diffusion path)
- efficient blood supply (animals)
- ventilation (animals)
what is osmosis ?
osmosis is the movement of water molecules from a solution with a high to low concentration of water molecules, through a cell’s partially permeable membrane.
what is meant when a solution is isotonic to a cell?
means the concentration of solute (i.e. sugar) is the same inside the cell as it is outside the cell.
Where does gases exchange happen ?
the Alveoli in the lungs
what is meant when a solution is hypotonic to a cell?
the concentration of the external solution is lower than that of internal solution (inside cell)
what may happen when an animal cell is placed in a very hypertonic solution?
water moves into the cell, causing it to burst.
what may happen when an animal cell is placed in a very hypertonic solution?
water moves out of the cell, causing it to shrivel up.
how do plant leaves and stems remain rigid?
turgor pressure - water moves in by osmosis causing the vacuole to swell and the cytoplasm to press against the cell wall.
what is permeable
Permeable means that things are allowed through
Partially
Partially means the membrane will only let certain things in pass through it
Why does water move?
Just like diffusion, particles want to be evenly spread out
what is active transport?
Active transport is the opposite of diffusion and osmosis as particles move from a low to high concentration, and
this process requires energy from respirations
how do plant root hair cells use active transport?
Root hair cells use active transport to take up mineral ions from a more dilute solution in soils.
how is active transport used to absorb the products of digestions ?
Active transport is used to transport glucose from a lower concentration in the blood.
Glucose is then transported in the blood.
Glucose is then transported to the tissues where it can be used in reparations.
food test for Reducing sugar
Benedict’s
Add Benedict’s reagent to the food and boil in a water bath
Blue to Brick red
food test for Starch
Iodine
Add iodine reagent to the food.
Yellow-brown to Blue-black
food test for Protein/amino acids
Biuret
Add Biuret reagent to the food.
Blue to Lilac/purple
food test for Fat
Ethanol
Add ethanol to the food to dissolve the fat then add water.
Colorless to White emulsion
sudan 111
What is the main function of the digestive system?
To digest food and absorb the nutrients obtained from digestion.
What is the role of the pancreas and the salivary gland in the digestive system?
The pancreas and the salivary gland are glands which produce digestive juices containing enzymes.
What is the role of the stomach in the digestive system?
Produces hydrochloric acid - which kills any bacteria present
provides the optimum acidic pH for the protease enzyme to function.
What is the role of the small intestine in the digestive system?
break down food
absorb nutrients needed for the body
get rid of the unnecessary components
is the site where soluble food molecules are absorbed into the bloodstream.
What is the role of the liver in the digestive system?
Produces bile (stored in the gallbladder) which emulsifies lipids and allows the lipase enzyme to work more efficiently.
What is the role of the large intestine in the digestive system?
Absorbs water from undigested food, producing feces
What is the role of enzymes in the digestive system?
Enzymes act as biological catalysts which speed up the rate of biological reactions (the break down of food) without being used up.
How does temperature affect enzyme action?
Up to a certain point, increasing temperature increases enzyme action, as molecules have higher kinetic energy.
Above a certain temperature, the shape of the active site in altered and the enzyme becomes denatured, so it can no longer catalyze the reaction.
The optimum temperature is around 37 degrees
How does PH affect enzyme function?
The optimum pH for most enzymes is around 7 (apart from protease in the stomach). If the pH is too extreme the shape of the active site may be altered and the enzyme may no longer work.
How does PH affect enzyme function?
The optimum pH for most enzymes is around 7 (apart from protease in the stomach). If the pH is too extreme the shape of the active site may be altered and the enzyme may no longer work.
Where are carbohydrases, produced in the body?
● Carbohydrases: amylase - salivary gland and pancreas; maltase - small intestine.
Where are proteases produced in the body?
● Proteases: pepsin - stomach; others - pancreas and small intestine.
Where are lipases produced in the body?
● Lipases: pancreas and small intestine.
What is the role of carbohydrases in the digestive system?
provide energy and food to the body and to the nervous system.
What is the role of protease in the digestive system?
Proteases break down proteins into amino acids.
What is the role of lipases in the digestive system.
Lipases break down lipids into fatty acids and glycerol.
How are the products of digestion used?
They are used to build bigger molecules such as carbohydrates and proteins. Glucose is used as a substrate in respiration.
Where is bile made and stored in the body?
Bile is made by the liver and stored in the gallbladder
Artery function
- Blood vessel that drains blood AWAY from the heart usually at high pressure
- very thick
- very stretchy
- very narrow
- no valve
Vein function
- veins carry blood under low pressure from the capillaries and return the blood TO the heart with low pressure
- quite thin
- not very stretchy
- wide
- has a valve
Lumen
The hollow space within a blood vessel
Capillary function and adaption
Blood vessels that allow for the rapid exchange of oxygen and nutrients for carbon dioxide and waste products
- one-cell layer think
- not stretchy at all
- wide
- no valve
- low pressure
Valve
A structure within a vein that prevents the backflow of blood on its return to the heart
Aorta
The largest ARTERY in the body that takes oxygenated blood OUT of the heart and TO the body’s tissues
Vena Cava
The largest VEIN in the body that takes deoxygenated blood TO the heart
Pulmonary Circulation
flood flow from the RIGHT side of the heart that takes deoxygenated blood to the lungs
