Topic J: Transport in cells and animals Flashcards
Define Diffusion?
Movement of particles from an area of high concentration gradient until an equilibrium is reached. Substance that the cells need are diffused through the membrane.
Define Osmosis?
Movement of water from an area of high water potential to a low water potential down a water potential gradient through a semi-permeable membrane, this requires no energy. Used root hair cells to absorb water.
Define Active Transport?
The movement of particles against the concentrating gradient (low-high) THIS REQUIRES ENERGY Used to transport proteins into and out of the cell.
Ways that substances move in and out of cells?
Diffusion, osmosis and active transport
Why can simple, unicellular organism rely on diffusion for movement of substances in and out of the cell?
This is because larger animals have a small surface area compared to the volume of them. Small surface area to volume ratio. this means that they require a circulatory system. Smaller organism do not need this because of the fact that they have a larger surface area to volume ratio.
Understand the need for a transport system in multicellular organisms?
This is because larger animals have a small surface area compared to the volume of them. Small surface area to volume ratio. this means that they require a circulatory system. Therefore they need a transport system to take substances across the body.
Explain how the heart rate changes during exercise due to the response of adrenaline?
the is because of the fact that more oxygen is needed (or is going to be needed) in parts of the body.
Describe the structure of an arteries?
Thick outer wall, made of muscle and elastic fibers, narrow lumen.
Describe the structure of capillaries?
very thin walls that are only one cell thick, so substances can be easily diffused.
Describe the structure of veins?
Thinner outer walls then arteries; because need low resistance, thin layer of muscle and elastic fibers.
Where to arteries carry the blood to and from?
carries blood from the heart to the tissues. (Away from the heart)
Where do the capillaries carry blood to and from?
carries blood from arteries to veins. (link them together) this is where the diffusion to the tissues take place.
Where do the veins carry blood to and from?
carries blood from the tissues (against gravity) back to the heart.
Is blood oxygenated in arteries, veins and capillaries?
arteries- yes. capillaries - going from oxygenated to deoxygenated. Veins- No
Blood pressure in arteries, capillaries and veins?
arteries- surging high pressure because of pulse from heart. capillaries - low pressure so substances can diffuse and only one cell thick. Veins - blood id at low pressure but changes with muscle contractions
Which is there valves in?
Veins
What does the pulmonary artery do?
carrys deoxygenated blood to the lungs.
What does the Pulmonary vein do?
carries oxygenated blood back into the heart
What do the Coronary Artery do?
these are the first blood vessels that branch off from the assending aorta, supplie oxygen to the heart.
What does the Vena Cava do?
the main vein of the body returning deoxygenated blood to the heart.
What does the Aorta do?
the main artery of the blood, carries blood to the rest of the body from the heart.
What is the composition of blood?
Red blood cells, white blood cells, platelets and plasma
What is Plasma?
A yellow liquid, 90% water, 10% dissolved substances
What are some of the things Plasma transports?
carries food e.g. glucose and amino acids, enzymes, hormones, antibodies, urea fro the liver to kidneys contains insoluble fibrinogen involved in blood clotting
adaptations of red blood cells?
no nucleus, red color due to presence of hemoglobin. Special donuts like shape so it is flexible.
What are platelets?
Red blood cells get trapped in threads. this forms a blood clot. blood clots stop blood loss and entry of germs.
What are Phagocytes?
lobed nucleus, cell can change shape. These surround and digest bacteria
What are Lymphocytes?
large nucleus. These produce antibodies that are specific to the bacteria or virus which will destroy them.
Why do red blood cells have these adaptations?
This is so that they are more suited to carrying oxygen and CO2.
Three ways in which the structure of an artery can differ form the structure of a vein?
Thicker wall More elastic tissue More muscle Smaller lumen No valves
Suggest why blood flow in a leg vein is slower when there is lack of movement?
This is because of the fact that there is, less or no muscle contraction. So there is nothing to squeeze the vein or push blood
Suggest why a clot that blocks the small blood vessels in the lungs can cause death?
Less or no oxygen /oxygenated blood to the heart etc.. Lack of respiration
What is in a Phagocyte?
- Lobed Nucleus - contains DNA, controls the cell.
- cytoplasm - chemical reactions take place here
- cell membrane - controls what enters and leaves the cell.
What happens to a bacterium after it has been ingested by a phagocyte?
Pathogen is broken down or dissolved using enzymes.
Describe how a different type of white blood cell can also help to prevent disease.
Lympocytes release antibodies which clump the bacteria, neutralizing it and making it non harmful.
Structure of Circulatory system and Heart?
LOOK AT MAP IN DIAGRAMS!
Describe structure of white blood cell?
Has a lobed Nucleus.
What affects may come with narrow arteries?
- Less blood transported.
- Higher pressure in arteries.
- Increased heart rate.
- Increased amount of lactic acid
- Clots .
- Death
