Organisation Flashcards
After the left _____ the blood goes through the _____ to the rest of the body.
ventricle, aorta
Blood comes back from the lungs to the _____ via the _____ _____.
heart, pulmonary vein
Briefly describe how an artificial pacemaker works.
Send strong, regular electrical signals to the heart to stimulate it to contract properly.
Describe 2 structural features of arteries
thick muscular walls, elastic layer in walls, narrow lumen.
Describe 2 structural features of capillaries
Narrow, walls only one cell thick.
Describe 2 structural features of veins
Wide lumen, valves
Give 3 adaptations of the red blood cell.
1) it has a biconcave shape for a higher surface area to volume ratio
2) It has no nucleus
3) it has a lot of haemoglobin
Give 3 things that plasma is made up of.
1) water
2) hormones
3) enzymes
4) products of digestion
5) urea
How does being biconcave help red blood cells with their function?
increase Surface area: volume for efficient diffusion.
Humans have a _____ circulatory system.
dual
Name a method to unblock a coronary artery in the heart.
Stent
name the lower chambers of the heart
right and left ventricles.
name the upper chamber of the heart.
right atrium and left atrium
State 2 differences in the blood flowing in arteries and veins.
oxygenated, more nutrients, less waste products in arteries.
State the function of white blood cells.
engulf pathogens, produce antibodies and antitoxins.
Substances can easily_____ through capillaries because they are _____ thick.
diffuse, one cell
the blood comes from the body, back to the _____ via the _____
right atrium, vena cava
The _____ blood is pumped to the lungs via the _____
deoxygenated, pulmonary artery
What 4 things does blood consist of?
Red blood cells, white blood cells, platelets and plasma
what are red blood cells?
biconcave cells that have haemoglobin - carry oxygen
What are the 3 types of blood vessels?
Arteries, Veins and Capillaries
What can be used to replace damaged valves?
biological or mechanical replacement valves
What can cause arteries to narrow.
fatty build up
what do coronary arteries do?
they supply blood to the heart.
what do platelets do?
when tissues are damaged and blood vessels cut, platelets clump together to stop bleeding and block the broken blood vessels.
What do statins do?
reduce cholestrol levels.
what is a dual circulatory system?
It is a system in which the blood passes through the heart twice before completing a cycle.
What is a natural pacemaker?
a group of cells in the right atrium that controls the resting heart rate.
what is plasma in the blood?
Yellow liquid that carries blood cells, proteins and dissolved substances around the body.
What is the function of the valves.
to prevent the backflow of blood.
what is the pigment found in red blood cells that binds to oxygen?
haemoglobin
What is the purpose of the circulatory system?
to pump blood around the body, which contains oxygen, glucose and products of digestion.
What two things are used for respiration?
oxygen and glucose
What type of tissue is the heart walls made up of?
Cardiac Tissue
When the atria contract, where does the blood go?
it goes through the valves and into the ventricles.
Where are the coronary arteries located?
on the outside of the heart.
Which organ system transports substances to and from body cells?
circulatory system
Which side of the heart has deoxygenated blood?
Right
Why is the muscle wall of the left ventricle thicker?
It needs to pump the blood all over the body so it needs to be stronger.
Why do arteries have thicker muscle walls than veins?
to withstand high blood pressure
What are organelles?
subcellular structures
What is a tissue?
a group of similar cells that work together to carry out a particular function
What is an organ?
a group of different tissues that work together to perform a particular function
In plants, what are leaves examples of?
organs
Why can we not just increase the temperature of our bodies to increase the rate of reactions within us?
damage to the cells
would speed up non useful reactions
requires lots of energy
What is a catalyst?
a substance that increases the speed of a chemical reaction without being used up or changed in the process.
What is an example of a biological catalyst?
enzyme
What is an enzyme?
a special type of catalyst made by a living organism
What are enzymes made up of?
long chain of amino acids as they are proteins
What is the name of special region of an enzyme that binds to the substrate?
active site
In order for an enzyme to catalyse a reaction, the active site of the enzyme must be _____________ to the substrate.
complementary
What is the lock and key model?
the idea that for an enzyme to catalyse a reaction, the substrate has to perfectly fit into the active site
What is the induced fit model?
in order for an enzyme to catalyse a reaction, the enzymes active site actually changes shape slightly as it binds to the substrate.
What does the term ‘optimum’ mean for enzyme temperature?
The temperature at which enzyme activity is highest
What affect does extremely high pH have on enzymes?
denatures them
What is the optimum temperature for enzyme activity?
37 C
Explain how increasing the temperature can cause an enzyme to denature.
High temperatures start to break the bonds holding the enzyme together
This causes the enzyme and it’s active site to change shape
This means the enzymes active site will no longer be complementary to the substrate
Which 3 biological molecules do we need in large quantities?
Carbohydrates
Lipids
Proteins
Why do we need carbohydrates?
To provide energy for chemical reactions
Why do we need lipids?
To insulate us and regulate our body temperature
To provide energy for chemical reactions
Which food group is the most important for growth and producing new cells?
proteins
Which vitamin or mineral ion is important for good vision and healthy hair and skin?
Vitamin A
Which disease can be caused by lack of vitamin C?
scurvy
Explain why it is important that we get enough iron in our diet.
Iron is an important component of haemoglobin
Haemoglobin is the protein in red blood cells that allows them to transport oxygen around the body
A lack of iron (and hence haemoglobin), can lead to anaemia, where we can’t transport enough oxygen to our tissues.
Which three elements are found in carbohydrates?
Oxygen
Carbon
Hydrogen
Where are carbs broken down?
mouth and small intestine
Is glucose a monomer or a polymer?
monomer
Is glycogen a monomer or a polymer?
polymer
What are the monomers that join together to form proteins called?
amino acids
proteins are mainly made from which 4 elements?
oxygen, hydrogen, carbon, nitrogen
Which 2 organs are proteins broken down in?
stomach and small intestine
What are lipids made of?
a single glycerol molecule and 3 fatty acid molecules
Where are lipids broken down?
small intestine
What is starch?
a polymer of glucose made by plants
What is starch broken down by and into what?
amylase into maltose
What is maltose broken down by and into what?
maltase into glucose
Which organs in the body produce amylase?
Small intestines
Pancreas
Salivary glands
What is protein broken down by and into what?
proteases into individual amino acids
Give 2 examples of protease enzymes?
pepsin and trypsin
Which organs in the body produce protease enzymes?
Pancreas
Small intestines
Stomach
What are lipids broken down by and into what?
lipase into glycerol and fatty acids
Is bile an enzyme?
no
How does bile help with the digestion of lipids?
It emulsifies the lipids which increases the surface area for lipase enzymes to break them down
Which organs in the body produce lipase enzymes?
Small intestines
Pancreas
What are the 2 main roles of the digestive system?
breaking down of foods
absorbing the nutrients into the bloodstream
What are the 3 roles of the stomach?
contract muscular walls to churn and mix the food
produce pepsin to break down proteins
produce HCl to provide right pH for enzyme and kill microorganisms
Where is bile made and stored?
made in the liver, stored in the gallbladder
What are the 2 roles of bile?
1)emulsify lipids for efficient breaking down
2) neutralise acids from the stomach
Where is bile released into?
the small intestine
Which enzymes does the pancreas produce?
Amylase, proteases, and lipases
Which enzymes does the small intestine produce?
Amylase, proteases, and lipases
What are villi?
Villi are finger-like protrusions of the small intestine that are responsible for absorbing nutrients into the body.
What are 3 way villi are adapted to their role?
there are many villi which gives them a large total surface area
They are 1 cell thick, efficient diffusion
good blood supply
have microvilli to increase surface area
What is the main role of the large intestine?
absorb water
What is the food test for sugars?
benedict’s test
What is the food test for starch?
iodine test
What is the food test for proteins?
biuret test
How do you carry out the Benedict’s test?
1) dissolve crushed up pieces of the food in water.
2) filter out the solution (the filtrate will be our sample)
3) take 5cm^3 of the sample, put it in a test tube and add 10 drops of benedict’s solution to the sample
4) put the test tube in a water bath at 75 C for 5 mins
If sugar is not present, solution will stay blue.
if sugar is present, solution will turn green, yellow or brick-red (increasing conc.)
How do you carry out the iodine test?
1) crush the food and put it in a dimple tile
2) put a few drops of iodine solution on the sample
if the sample turn blue-black, starch is present
if the sample remains the same, no starch is present
How do you carry out the biuret test?
1) dissolve crushed up pieces of the food in water.
2) filter out the solution (the filtrate will be our sample)
3) take 2cm^3 of the sample, put it in a test tube and add 2 cm^3 of biuret solution to the sample
4) shake to mix
If protein is present, solution will turn lilac/purple
if not then solution will remain blue
what is the food test for lipids?
emulsions test
How do you do the emulsion test?
1) dissolve crushed up pieces of the food in water.
2) filter out the solution (the filtrate will be our sample)
3) take 5 cm^3 of the sample, add 2 cm^3 of ethanol and shake vigorously
4) add 2cm^3 of distilled water
if it goes cloudy white, lipids are present
if not then lipids were not present
Which chemical process supplies the majority of the energy required for the contraction of muscle tissue?
Aerobic respiration
What is coronary heart disease?
fatty build up in the coronary arteries causes a narrower lumen and decreases blood supply. This deprives cardiac muscle of oxygen and nutrients causing chest pain and heart attack.
The fatty material that builds up in coronary arteries is sometimes known as :
fatty plaques.
What are 2 treatments for CHD?
statins and stents
How does a stent help treat coronary heart disease?
It expands within the artery to widen the lumen
What are the benefits of stents when treating coronary artery disease?
The stents have an almost immediate effect
The stents can last a long time
Surgery is quick
How do statins help treat coronary heart disease?
they decrease the cholesterol in the body
What are the disadvantages of statins when treating coronary artery disease?
They have side effects such as kidney failure and headaches
It can take months to see the positive effects
The pills have to be taken every day
What are two problems that may be caused by faulty heart valves?
Not enough blood can pass though the valve
Blood can pass backwards through the valve
What 2 types of valves can replace faulty heart valves?
biological - from other animals such as pigs and cows
mechanical - man made often from metal
What are the 2 treatments for heart failure?
replacement with artificial or biological heart
Which type of heart replacement might be rejected by the immune system?
biological
What do we mean by ‘communicable’ diseases.
Diseases that can be spread from person to person
What is the role of the immune system?
To detect and destroy pathogens
If your immune system is weakened, which type of diseases do you become more susceptible to?
Communicable diseases
What are 2 examples of non-communicable diseases?
cancer
diabetes
What is bronchitis?
Inflammation of airways in the lungs
What is a tumour?
an abnormal mass of cells formed when cells undergo uncontrolled growth and division
What are the 2 types of tumours?
benign and malignant
Which type of tumour is a cancer?
malignant
What is the difference between benign and malignant?
benign tumours stay in one place making it easy to get rid of them, but malignant tumours can spread through the body to be fatal
What are 3 risk factors of cancer?
smoking, obesity, UV radiation, alcohol
Tumour cells divide by which type of cell division?
mitosis
What are stomata?
holes in the underside of the leaf to allow for air and water to come in and out
What is the structure of the leaf from top to bottom?
waxy cuticle
upper epidermis
palisade mesophyll
spongy mesophyll
lower epidermis
What are the characteristics of the lower epidermis layer?
has stomata and guard cells to allow carbon dioxide to come in and water to go out
What are the characteristics of the spongy mesophyll layer?
lots of gaps for carbon dioxide to flow into
What are the characteristics of the Palisade mesophyll layer?
lots of palisade cells, filled with chloroplast as majority of photosynthesis takes place here
What are the characteristics of the upper epidermis layer?
epidermal tissue, that are almost transparent to allow for light to pass through to the palisade cells
What are the characteristics of the waxy cuticle layer?
water proof lipid layer to decrease water loss
What do the guard cells do?
they control the opening and closing of the stomata
What is the term used to describe the open guard cells?
turgid
what is the term used to describe the closed guard cells?
flaccid
Why do the stomata close at night?
the guard cells are sensitive to light so they close at night
What are meristem tissue?
tissue found at the tips of roots and shoots which have stem cells
the leaf is an organ, true or false?
true
What 2 substances do plants transport?
sugars and water
What is translocation?
the transport of sugars through the plant
What is transpiration?
the uptake of water from the soil to the leaves
What do phloem transport?
sugars solutions
What do xylem transport?
water and mineral ions
How are the phloem cells arranged?
they from a tube by attaching on top of one another. Between each cell there are pores allowing for the movement of cell sap.
What is cell sap?
a mixture of water and sugar
How are xylem cells arranged?
they are arranged in a tube like phloem, but they are all dead so they connect directly to one another. They are strengthened by lignin to remain turgid
What is the transpiration stream?
water evaporating through the leaves causes water to be pulled up from the xylem. This means more water get pulled into the roots through osmosis from the soil. This is the transpiration stream.
What are the 4 factors that influence the rate of transpiration?
temperature
light intensity
air flow
humidity
How do root hair cells absorb mineral ions from the soil?
Active transport
Why does water loss slow down if a plant is put into a plastic bag?
The humidity increases
