Biology Flashcards
What are Eukaryotic cells?
- plants
- animals
The _________ contains the cell’s genetic material (in the form of DNA), and so controls the cell’s activities.
Nucleus
what is the function of the nucleus?
- stores genetic materials
- controls cells activity
What are ribosomes?
- where proteins are made
Where are proteins made?
ribosomes
what is the site of protein synthesis
another word for ribosomes
What is the cytoplasm?
A jelly-like material containing nutrients and salts, where chemical reactions take place
what is the mitochondria?
generate the energy necessary to power cells
- Mitochondria are the site of aerobic respiration, so they release energy for the cell.
What is a vacuole?
The vacuole is a large sac in the middle of the cell that contains a watery solution of sugars and salts (cell sap). It helps maintain the structure and shape of the cell.
The ___________ is made of cellulose. This makes it strong and allows it to maintain the shape of the cell.
cell wall
Bacteria are classed as ___________ organisms.
prokaryotic
What are plasmids
What is mitosis and meiosis?
two types of cell division
talk about the genetic materials in eukaryotic cells:
cells that contain genetic material called DNA enclosed in a nucleus
talk about the genetic materials in prokaryotic cells:
genetic material is not enclosed in a nucleus
prokaryotic cells are much smaller than eukaryotic cells, true or false?
true
how is the structure of genetic material in prokaryotic cells?
the genetic material is a single loop of DNA
what are plasmids?
small rings of DNA
prokaryotes have a cell membrane and cell wall true or false?
true but bacterial cell wall not plant cell wall
do prokaryotes have cytoplasm?
yes
stages of mitosis
1- first stage- ~DNA replicates to form 2 copies of each chromosomes
- cell grows and copies its internal structure such s mitochondria and ribosomes
2- mitosis takes place
- one set of chromosones is puleed to each end of the cell.
- the nuclei divides
final
- cytoplasm and cell membrane divide to from 2 idenrtical cells
Function of mitosis:
1- essential for growth and development of multicellular organisms
2- mitosis takes place when an organism repairs itself (broken bone)
3- mitosis happens during aesexual reproduction
meaning of diffusion:
net movement of particles from an area of higher concentration to an area of lower concentration
osmosis meaning:
net movement of water from a high concentration gradient to a low concentration gradient
what are enzymes:
catalysts which speed up a reaction
what is a tissue
a group of cells w similar structure and function
What is an organ?
a group of tissues that work together for a specific function
What are the three main nutrients of
carbohydrates, protein and lipids
What happens during digestion?
large food molecules are broken into small molecules by ezymes. the small molecules can be then absorbed into the blood streams
first step of digestion
food chewed in the mouth, ezymes in the salive begin to digest the starch into smaller molecules
second step of digestive system
the food passes down the oesophagus into the stomach, in the stomach ezymes begin digestion of proteins
3 step of digestion:
fluid passes down the small intestine
what is hydrochloric acid?
is what the stomach contains that helps the enzymes to digest proteins
what do the churning action of the stomach muscle do:
turns the food into a fluid increasing the surfgace are for ezymes to digest
step 4 of digesting
chemicals released into the small intestine from the liver and pancreas
what does pancreas do in digestion:
it prodcues enzymes which continue digestion of starch and protein. they also start the digestion of lipids
what is the function of bile
released from the liver, bile helps w the speed up of lipids. bile also neutralises the acid released from the stomach
what happens in the digestive system?
large food molecules are digested into smaller molecules and thenproducts of digestion are absorbed into th bloodstream
what is active trasnport
what is a simplified explnanation of how enzymes work?
the lock and key hypothesisi
what is the lock and key hypothesis?
1-the shape of the substrate is complementary to the shape of the active site,so when they bond it forms an enzyme- substrate complex
2- once bound, the reaction takes place and the products are released from the surface of the enzyme
what are enymes?
proteins
what is the optimum temperature?
body temperature- 37 degree celcius
what happens to the shape of the substrate when its too hot?
the substrate will not be complementary to the enzyme anymore
what does it mean when an enzyme is denatured?
when the subtrate changes
hows the optimum pH in the stomach?
acidic, low optimum pH
what happens when the pH is too low or too high?
teh forces that hold the amino acids will be affected
does denatured mean that an enzyme can no longer work? yes or no
yes
what do carbohydrases do?
convert carbohydrates into simple sugars
what does amalyse do?
breaks down starch into maltose
where is amylse produced?
salivary glands, pancreas and small intestine, and they break down carbohydrates
what do proteases do?
convert proteins into amino acids
where is pepsin produced
stomach, pacreas, small intestine
what do lipases convert
lipids into fatty acids and glycerol
where is lipases produced?
pancreas and small intestine
soluble glucose, amino acids, fatty acids and glycerol pass into the bloodstream to be carrried to all the cells in the body.; what do they build
carbohydrtes, lipids, proteins, withsome glucose used for respiration
read
benedict test- blue-black for starch
iodine test- blue-black (starch)
biuret test- purple for protein
where is bile produced ands found?
- found in liver
- sto0red in gallbladder
what does bile do: 2
1- alkali so neutrqalises hydrochloric qacid coming from the stomach
2- breaks down large drops of fats into smaller
true or false, the human body has. double circulatory system, while a fish has a single
true
what is the purpose of a double circulatory system?
- there are 2 circuits
deoxygenated blood flows into the right atrium and then into the rigght ventricle which pumps it to the lungs to unergo gseous exchnge
oxygenated blood flows into the left trium and then into the left ventricle which pumps oxygenated blood all around the body
structure of the heart: -
- muscular walls to provide a strong heartbeat
- muscular wall of left ventricle thicker as blood needs to be passed down all around the body
- 4 chambers that separte oxygenated and deoxygenated blood
- valves- make sure the blood does not flow backwards
coronary arteries- cover the heart to provide its own oxygenated blood supply
what do coronory arteries do?
supply blood to the heart muscle
how id the heartarte controlled?
controlled through peacemaker (cells found in the right atrium)
what do peacemakers do?
- provide small electrical impulses which pass through the heart muscle, causing it to contra t.
what is an artificial peacemaker and what does it do?
artificial peacemaker used for irregular heartbeats, it produces signals causing your heart to beat at a normal speed
what are the 3 main types of blood vessels in the body
- capillaries
- arteries
- veins
what do AAArteries do?
AAAAA- carry blood away from the heart
what do capillaries do?:
- opposite of arteries, carry blood back to the heart
what do veins do?
exchange nutrients+oxygen with tissue
Which of the following substances are nutrients that are exchanged between the blood in the capillaries and the body tissues?
amino acids and glucose
