paper 1 Flashcards
What are the benefits of using an electron microscope inside of a light microscope?
Light microscopes, allow you to visualise finer details including organelles
What’s the difference between a light, microscope and electron microscope?
Light microscopes are cheaper to make and they allowed to see the outlines of cells. Electron microscopes are more expensive, but they allow you to see finer details as they are have a greater resolving power and higher resolution.
How do you convert micro meters to millimetres?
Divided by 1000
What is the main difference between eukaryotic cells and prokaryotic cells?
eukaryotic cells have a nucleus prokaryotic cells do not that unity material is contained in plasmids
What extra organelles do plant cells contain that animal cells do not?
cell wall made of cellulose for more structure and protection
a permanent vacuole which stores sap
chloroplast is made of chlorophyll, which is used for photosynthesis
How do bacteria reproduce?
by binary fission
if bacteria divided every 10 minutes after an hour, how many bacteria will be produced?
1 hour = 6x10minute
so you would do
2^6= 64
What is a diploid cell?
A cell that has 23 pairs of chromosomes does a normal human cells
What is a haploid cell?
so that only has 23 chromosomes does a gametes (sperm and egg cells)
What is the function of mitosis?
To grow and repair cells
describe the process of mitosis
The nucleus, dissolves/divides and genetic material is duplicated
The two sets of chromosomes are moved to different sides
The mitochondria and ribosomes and other organelles duplicate
The cell divides producing to genetically identical diploid cells
What are stem cells and where are they found?
stem cells are undifferentiated cell that can be specialise to perform specific functions they found in animal embryos and plant meristems
In animals, where are stem cells made throughout the life
in the bone marrow, but these cab only specialised into blood cells
What’s the purpose of an embryo cloning?
embryo clones can be made of a person to harvest stem cells from, these can then be used to treat conditions without the cells being rejected by the patient’s body can also be used to preserve species or produce crops with desired traits
What is an example of a passive movement
Diffusion as it requires no energy. It’s the movement of particles from an area of high to low concentration down the concentration gradient.
How can I rate of diffusion be increased?
increasing the difference in concentration
Increasing the surface area
Increasing the temperature
What is the purpose of osmosis?
to balance the concentration of solution inside and outside of cell
What is active transport?
The movement of particles through a membrane via carrier proteins against the concentration gradient, which means it requires energy, hence the need for carrier proteins
What is the purpose of the digestive system?
to break down large insoluble molecules into smaller soluble molecules, so that nutrients can be absorbed from foods eaten and used in the body
What parts of the body are involved in the digestive system?
The teeth
Saliva
Stomach
Large intestine
small intestine
pancreas
Liver
what is the function of the teeth and saliva in the digestive system?
The teeth break down food mechanically, and the saliva contains amylase, which are a type of enzyme, and these also start the process of breaking down food
What is the function of the liver in the digestive system?
The liver produces bile which is stored in the gallbladder before going to the small intestine bile emulsify lipids to form droplets increasing the surface area. I love him to be better absorbed or disposed of
What is the function of the pancreas in the digestive system?
The pancreas secretes amylase, which breaks down starch into glucose in the small intestine
How is nutrients, absorbed into the bloodstream?
nutrients like glucose, absorbed into the bloodstream by Villi in the small intestine. However, it cannot absorb starch this way because it’s too large.
How is water absorbed into the bloodstream?
Through the large intestine
how does the stomach break down food?
The stomach contains hydrochloric acid and enzymes which chemically break down food. It’s also a muscle which turns up food
What is the lock and key principle?
every enzyme is specific, it only breaks down substrate that fits its active site this is called an enzyme substrate complex
What are the three different types of enzymes and what did they break down?
carbohydrates breakdown carbohydrates into simple sugars
Protease break down proteins into amino acids
Lipases breakdown are lipids into glycerol and fatty acids
What can cause an enzyme to denature?
Is the temperature or pH of its environment becomes too high
What is the food test for testing for starch?
Using iodine if starch is present, it turns from orange to black
how do you test for the presence of sugar is?
Using a Benedicks solution if the sugars are present, it turns from blue to orange 
how do you test for the presence
proteins?
using a biuret’s reagent of proteins are present, tense from blue to purple 
How do you test for the presence of lipids?
using cold ethanol flip is a presence it goes from clear to cloudy
What components of the body are involved in the respiratory system?
The trachea
The bronchi
Bronchioles
Alveoli
How does oxygen end up in the bloodstream?
oxygen diffuse into the bloodstream and binds to haemoglobin in red blood cells to be transported. It does this to the alveoli
What does fuses in and out of the alveoli?
Oxygen diffusers in common dioxide and water diffuses out
Describe the movement of blood through the heart
deoxygenated blood enters the right side of the heart through the vena cava into the right atrium, where it then passes through a valve into the right ventricle. It then exits, the heart through the pulmonary artery and the blood goes to the lungs. Oxygenated blood then re-enters the heart through the pulmonary vein and goes into the left atrium where it then passes through a valve into the left ventricle,and back out the heart through the aorta, where the blood is carried to the rest of the body.