Unit 1 Flashcards
Which bonds in a protein are fairly strong and therefore not broken down easily
Disulfide
Which bonds are formed between the carboxyl and amino acid groups and are easily broken by changes in PH
Ionic
Explain the test for proteins
Place a sample in a test tube and add an equal volume of sodium hydroxide solution
Add a few drops of very dilute copper sulphate solution and mix gently
A purple colour action indicates peptide bonds and therefore a protein
What is the name if the test for proteins
Biuret test
What colour will the solution remain when testing for proteins if proteins are not present
Blue
Fibrous proteins form what functions
Structural
Globular proteins carry out what functions
Metabolic functions
Given an example of a fibrous protein
Collagen
Given an example of a globular protein
Enzymes or haemoglobin
What are the limitations of the transmission electron microscope
Whole System must be in a vacuumed so living organisms can’t be observed
A complex staining process is required
The specimen must be extremely thin
The image may contain artefacts
What can the SEM do that the TEM not do
Produce a 3d image
Which has a higher resolution the TEM or the SEM
TEM
A bactira is what type of cell.
Prokaryotic
The folds in the double membrane of the mitochondria that form extensions are know as what
Cristae
The remainder of the mitochondria that is formed of a semi rigid material containing protein lipids and traces of DNA is known as what
Matrix
What are the functions of the rough endoplasmic reticulum
Provide a large surface area for the synthesis of proteins and glycoproteins
Provide a path way for the transport of materials especially proteins throughout the cell
What are the functions of the smooth endoplasmic reticulum
Synthesise, store and transport lipids
Synthesise, store and transport carbohydrates
What are the functions of the Golgi apparatus
Add carbohydrate to proteins to form glycoproteins
Produce secretory enzymes such as those secreted by the pancreas
Secrete carbohydrates such as those used in making cell walls
Transport modify and store lipids
Form lysosomes
What are the functions of lysosomes
Break down material ingested by phagocytic cells
Release enzymes to the outside of the cell
Digest worn out organelles so chemicals they are made of can be reused
Completely break down cells after they have died
What type of of ribosomes are found in eukaryotic cells
80S
What type of ribosomes are found in prokaryotic cells ?
70S
What are the roles of lipids
Energy source
Waterproofing
Insulation
Protection
What is the name of the test for lipids
Emulsion test
Explain the test for lipids
Take dry grease free test tube
Take 2cm of sample an add to 5cm of ethanol
Shake thoroughly to dissolve any lipid sample
Add 5cm of water and shake gently
A cloudy white colour indicates the presence of lipids
In a phospholipid the head is what
Hydrophilic
In a phospholipid the tail is what
Hydrophobic
What are the 3 bonds formed in proteins ?
Disulfided
Ionic
Hydrogen
Why are pathogens that show a lot of antigenic variability would cause a vaccine to be ineffective
Antigen changes so specific antibody no longer binds to new antigen
Many different strains so not possible to make a vaccine with all antigens
Name 6 ways that substances can cross the cell surface membrane other than diffusion
Osmosis Co-transport
Facilitated diffusion
Active transport
By phagocytosis
Exocytosis- fusion of vesicle with cell surface membrane
Explain facilitated diffusion
Use of channel/ carrier protein
Down concentration gradient
What is an atheroma
A fatty deposited in the wall of the artery
What does the aorta do ?
Connected to the left ventricle carries oxygenated blood to all parts of the body apart from the lungs.
What is the function of the vena cava?
Connected to the right atrium brings back deoxygenated blood back from the tissues of the body
What is the function of the pulmonary artery
Connected to the right ventricle carries deoxygenated blood to the lungs where oxygen is replenished and it’s carbon dioxide is removed
What type of blood does the pulmonary artery carry
Deoxygenated blood
What is the function of the pulmonary vein?
Connected to the left atrium and brings oxygenated blood back from the lungs.
What type of blood does the pulmonary vein carry
Oxygenated blood
The heart is supplied blood by what vessels
Coronary arteries
The contraction of the heart is known as what
Systole
The relaxation of the heart is known as what
Diastole
What are the 3 phases of the cardiac cycle
Diastole
Atrial systole
Ventricular systole
(That order)
Valves in veins are known as what?
Pocket valves
What is the definition of stroke volume
Volume of blood pumped out by one ventricle at each beat
What is the formulae for cardiac output
Cardiac output = stroke volume x heart rate
What is the definition of cardiac output
The volume if blood pumped out by one ventricle of the heart in one minute
What are the sequence of events that control the cardiac cycle
A wave of electrical activity spreads out from the SAN causing both atria to contract top down
A layer of non-conductive prevents the waves crossing to the ventricle
The wave passes through the AVN
The AVN after a short delay conveys a wave of electrical activity to the bundle of His
The bundle of His conducts the wave to the base of the ventricles
This moves through the purjkine fibres causing the ventricle to contract up
What is thrombosis
Formation of a blot clot within a vessel that may lead to a blockage
What happens in thrombosis
An atheroma brakes through the endothelium lining of a blood vessel and forms a rough surface that interrupts the smooth flow of blood
How does an aneurysm form
Atheroma that lead to the formation if thrombus weaken the artery walls.
The weakened points swell to from ballon like blood filled structures
What is it called if an aneurysm busts
Haemorrhage
Name 4 risk factors of CHD
Smoking
High blood pressure
Blood cholesterol
Diet
What are the two nonspecific defence mechanisms
Physical barrier eg. Skin
Phagocytosis
What are the specific defence mechanisms
Cell mediated response - t lymphocytes
Humoral response - b lymphocytes
Explain the process of phagocytosis
Chemicals produce by pathogen attract phagocytes
Phagocytes attach them selves to the surface of the pathogen
They engulf the pathogen to form a vesicle known as a phagosome
Lysosomes move towards the vesicle and fuse with it
Enzymes with in the lysosomes break down the pathogen
What is the response from t lymphocytes to infection from a pathogen
Pathogens invade body cells or are taken over by phagocytes
The phagocyte places antigens from the pathogen on its cell surface membrane
Receptors on certain T helper cells fit exactly onto these antigens
This activates other T cells to divide rapidly by mitosis and form a clone
What do cloned T cells do
Develop into memory cells that enable a rapid response to future infections from the same pathogen
Stimulate phagocytes to engulf pathogens by phagocytosis
Stimulate B cells to divide
Kill infected cells
Plasma cells are what stage of immune response
Primary
What do plasma cells do
Secrete antibodies directly to destroy the pathogen and the toxin it produces
What stage of immune response are memory cells
Secondary
What do memory cells do
Circulate in the blood and when they encounter the same pathogen at a later date they divide rapidly and develop in to plasma cells and more memory cells
How do B cells carry out there role in immunity
The surface antigens of the invading pathogen are taken up by B cells
The B cells process the antigens and present them on their surfaces.
T helper cells attached to the processed antigens on the B cells thereby activating them
B cells activated divided by mitosis to give a clone of plasma cells
The cloned plasma cells produce antibodies that are specific to the antigens on the pathogen
Antibodies attach to the pathogens antigens and destroy them
Some B cells develop into memory cells
What is the definition of diffusion
The net movement of molecules or ions from a region with high concentration to region with low concentration
The more negative the value for water potential the what?
The lower the water potential
How are microvilli adapted for their function
Increase surface area for diffusion
Very thin walled
Able to move so help maintain gradient
Good blood supply
When the internal intercostal muscles contract what happens
Expiration
The contraction of the external intercostal muscles cause what
Inspiration
What is the equation for pulmonary ventilation
Pulmonary ventilation= tidal volume x ventilation rate
What are the essential features of a gas exchange system
Large Surface Area to volume ratio Very thin Partially permeable Movement of environmental medium Movement of internal medium
What is the role of the alveoli in gas exchange
Red blood cells are slowed
Reduce diffusion distance as red blood cells are flattered against capillary wall
Thin walls reduce diffusion distance
Large surface area
Blood flow through capillaries maintains concentration gradient
What are the symptoms of TB
Persistent cough
Tiredness
Loss of appetite
Fever and coughing up of blood as disease develops
