Genes and health + Voice of the genome Flashcards
what are the 4 main components of blood?
- plasma
- platelets
- white blood cells
- red blood cells
what is an open circulatory system?
where blood is pumped by the heart into body cavities, where tissues are surrounded by blood
what is a closed circulatory system?
where the blood always stays in the vessels and never directly contacts cells
what is a single circulatory system?
where the blood flows through the heart once per cycle
what is a double circulatory system?
where the blood flows through the heart twice per cycle
name 3 advantages of a double circulatory system?
- pressure can be maintained
- cells have a high metabolic rate
- prevents the mixing of blood, so the o2 content stays high
what is mass transport?
the bulk movement of gases or liquids in 1 direction
name 4 things needed for a mass transport system?
- a system of vessels
- a way of making sure substances movwe in the right direction
- means of moving materials
- a transport medium
name 3 benefits of mass transport?
- move substances quicker
- maintains concentration gradients
- ensures effective cell activity
what is a pulmonary circuit?
blood moving from heart to lungs
what is a systemic circuit?
blood moving from the heart to the body
what does the umbilical artery do?
takes blood from the feotus to the placenta
what is the order of blood vessels?
arteries - arterioles - capilleries - venuoles - veins
what is collagen?
connective tissue
where are veins situated and what does this do?
near large muscle groups, so when they contract they squeeze the veins, helping maintain pressure
what do valves do?
keep blood flowing in the right direction
name 2 reasons that mass transport is better than diffusion?
- faster
- transports substances over longer distances
name the 5 main functions of blood?
- transports excretary products
- transports digested food
- transports hormones
- maintains body temp
- buffer to PH changes
how many binding sites does a heamoglobin molecuole have?
4
what is special about heamoglobins cytoplasm and why?
it has low oxygen levels, to maintain a steep gradient
what does high oxygen affinity mean?
binds easily, dissociates slowly
what does low oxygen affinity mean?
binds slowly, dissociates easily
what does partial pressure of oxygen mean?
oxygen concentration
if a partial pressure graph shifts to the right what does that mean?
lower oxygen affinity, so it dissociates easier
if a partial pressure graph shifts to the left what does that mean?
higher oxygen affinity, so oxygen loads easier in the lungs
what partial pressure shift should a small/active organism have?
right
what is the name fore heamoglobin that has binded to C02?
Carbiminiheamoglobin
what percentage of CO2 is carried by plasma?
5%
what percentage of CO2 is carried in heamoglobin?
10 - 20%
how is most CO2 in the body stored?
it reacts with water to form carbonic acid, with the help of the enzyme carbonic anahydrase
what happens to CO2 in the lungs?
the reaction is reversed and CO2 diffuses out into the lungs
what does carbonic acid separate into?
H+ ions and hydrogencarbonate ions
name 2 reasons for blood clotting?
- prevent blood loss
- prevent entry of pathogens
what is thrombosis?
the process of clotting
what is seratonin?
hormone that causes smooth muscle to contract, constricting blood vessels
what is thromboplastin?
an enzyme which controls formation of a clot
name the 4 steps of blood clotting?
1) thromboplastin catalyses the conversion of prothrombrin into an enzyme called thrombrin using calcium ions
2) thrombrin also converts fibrinogen which converts into fibrin which forms a mesh of fibres
3) more cells and platelets fall into the mesh, building the clot
4) special protiens in the platelets contract, tightening the clot
name the 3 types of valves?
- tricuspid valve
- bicuspid valve
- semi-lunar valves
how many semi-lunar valves are there?
2
where is the tricuspid valve located?
between the right atrium and right ventricle
where is the bicuspid valve located?
between left atrium and left ventricle
where are the semi-lunar valves located?
- between the right ventrical and pulmonary artery
- between the left ventricle and aorta
what do the tendonis cords do?
ensure the valves aren’t turned inside out
what supplies blood to the heart muscle?
the coronary artery
what does systole mean?
hearts contracting
what does diastole mean?
heart is relaxed
what is a cardiac cycle?
1 sequence of filling and pumping blood in the heart
what type of muscle is the heart?
myogenic
what 4 things happen during diastole?
- atria and ventricles relax
- elastic recoil lowers the pressure
- the semi-lunar valves close
- veins draw blood into the atria
what happens during atrial systole?
the atria contract, forcing blood into the ventricles
what happens during ventricular systole?
the ventricles contract, pushing blood out the heart
what does myogenic mean?
it initiates its own contractions
name the 2 nodes that control the cardiac cycle?
- sinoatrial node
- atrioventricular node
where is the sinoatrial node?
above the right atrium
where is the atrioventricular node?
near the atrioventricular valve
name the 6 steps of a full cardiac cycle?
1) SAN sends out a wave of electrical excitation
2) atria contract, blood flows through tricuspid valve
3) after a short delay, the AVN sends out a wave of electrical excitation
4) then the “bundle of his” transfers the signal don to the septum
5) then, the impulses are conducted by purkinje fibres
6) ventricles contract from the base, upwards so blood leaves the heart
name 3 things that affect pressure in the heart?
- contractions
- filling with blood
- state off valves
name 3 things that affect pressure in the heart?
- contractions
- filling with blood
- state off valves
why do valves open?
to allow movement of blood into a certain area
why do valves close?
to prevent the backflow of blood
what is the equation for stroke volume?
cardiac output X heart rate
how does caffiene work?
stimulates production of noradrenaline by inhibiting release of adenosine, this triggers an increase in heart rate , meaning blood is pumped faster and oxygen is delivered to muscle and brain tissue at a higher rate.
what is noradrenaline?
a neurotransmitter usually released during “fight or flight” situations
what is adenosine?
a depressant
what are daphnia?
aquatic crustaceans
what is atheroma?
fatty deposit in the arterys
what is an endothelium?
inner cell lining of blood vessels
what is athlerosclerosis?
a disease affecting blood vessels, causing CVD and strokes.
what are the 6 steps of athlerosclerosis?
1) endothelium is damaged
2) inflammatory response is caused
3) atheroma builds up
4) plaque forms due to calcium salt and fibrous tissue deposition
5) as a result, the artery stiffens
6) positive feedback occurs, causing more inflamation
what is epidimiology?
the study of people, patterns, causes and effects of diseases
what is the calculation for blood pressure?
force / SA of vessel
how does salt affect blood pressure?
it increases water retention in the blood, increasing blood pressure
what does hypertension mean?
high blood pressure
how do you present blood pressure?
systolic pressure / dystolic pressure
name 6 treatments for CVD?
- ACE inhibitors
- calcium channel blockers
- diuretics
- statins
- anticoagulants
- platelet inhibitors
what do ACE inhibitors do?
relax veins and arteries to lower blood pressure
what do calcium channel blockers do?
prevent calcium entering artery walls, weakening contractions
what do diuretics do?
prevents build up of water in the blood, lowering blood pressure
what do statins do?
lower LDL cholesterol levels
what do statins do?
lower LDL cholesterol levels
what is the function of the nucleolus?
dark spot in the middle of the nucleus, site of ribosome formation
what is the function of the nuclear envelope?
Transports RNA and protiens in and out of the nucleus
what is the function of the amyloplast?
energy store
what is the function of the plasmodesmata?
connects cytoplasm of neighbouring cells, allows substance transport
what is the function of the golgi body?
modifies protiens and lipids
what is the function of the tonoplast?
vacule membrane, regulates ion movement
what is the function of the middle lamella?
cement layer between plant cells
what is the function of the smooth ER?
makes lipids and steroids
what is the function of the rough ER?
produce proteins
what valves open and close during diastole?
- SL valves are closed
- AV valves are open
what valves open and close during atrial systole?
- AV valves are open
- SL valves are closed
what valves are open during ventricular systole?
- AV valves are closed
- SL valves are opened
what is a transcription factor?
protiens that bind to DNA and regulate gene expression
where can transcription factors bind?
promoter region
enhancer region
what does a promoter region do?
increase transcription
what does an enhancer region do?
decreases transcription
what is an operon?
unit of linked genes that regulate protien synthesis
what is a repressor protien?
prevents transcription when activated
how does a repressor deactivate in ecoli?
lactose binds to it to remove it by changing its shape
what is a promoter?
starting point for transcription
what is an operator?
binding site of repressor
what is epigenetics?
genetic control by factors other than DNA sequence
what are the 2 main method for epigentics?
- histone modification
- DNA methylination
what is Histone modification?
when DNA is tightly wrapped around the histone transcription is much harder, and vise versa
what is DNA methlynation?
adds a methal group to DNA at a CPG site, preventing transcription
what does sexual reproduction in plants involve?
transfer of pollen between male and female parts
what is the anther?
where pollen is produced
what is the stigma?
part of the female reproductive organ which receives pollen
what is the ovary?
part where female gametes are located
what gender produces pollen?
male
what happens after pollination occurs? (4 steps)
- pollen grain germinates, and a pollen tube rows down the style to the ovary
- 2 haploid male nuclei move down tube
- generative nucleus divides by mitosis to form 2 haploid male nuclei
- As the pollen tube reaches the ovule, the pollen tube nucleus breaks down and the two haploid male nuclei pass into the ovule so that fertilisation can occur
what are the 2 nuclei in the pollen tube called?
- pollen tube nucleus
- generative nucleus
whats a style?
tube-like structure in which connects stigma and ovary.
how do steroid hormones pass through cell membranes?
theyre lipid soluble
