B1 Core Science Concepts Flashcards
Why do we need exchange surfaces?
To remove the waste products
What substances need to be removed from the body?
Carbon dioxide
Urea
How does the body make sure it gets the basic requirements for sustaining life?
By specialised exchanged surfaces and transport systems
What are specialised surfaces needed for?
To meet the demand of high activity levels in multicellular organisms
What are transport systems needed for?
To deliver materials to and from the exchange surface
What are the features of a good exchange rate?
Permeable
Very thin membranes
Why do exchange surfaces need to be permeable?
So that substances can readily diffuse in and out of the cell
Why is thin membranes important in in exchange surfaces?
Diffusion is the only effective over short distances
What is the relationship between the size and surface area to volume ratio of organisms?
As the organism gets bigger, the surface area to volume ration get smaller.
What are the 3 main things cell membranes are made of?
Phospolipds
Cholesterol
Protein
What does the cell membrane do?
Regulates the transport of materials entering and exiting the cell
What is the function of phospholipids in the cell membrane?
To arrange themselves into a bilayer with polar head exposed to the outside and inside the cell
What is the function of cholesterol in the cell membrane?
Regulates the fluidity and permeability of the membrane
What is the function of integral proteins in the cell membrane?
To transport large molecules across the membrane
What is the function of peripheral proteins in the cell membrane?
They are involved in the communication and some transport
What is the function of glycoproteins in the cell membrane?
Involved in cell recognition
What are the 3 different types of passive transport?
Osmosis
Simple diffusion
Facilitated diffusion
What is the difference between active and passive transport?
Active transport requires energy
Passive transport DOES NOT requires energy
What is the exchange surfaces in the human respiratory system?
Alveoli in the lungs
What is the transport system used for?
Delivers materials to and from the exchange surfaces
What is diffusion?
The movement of molecules from and area of high concentration to low concentration
What is the fluid mosaic model?
This model describes the arrangement of molecules in the membrane: fluid bc the phospholipid are constantly moving and mosaic bc the proteins molecules are scattered throughout the phospholipids like tiles in a mosaic
What is complimentary base paring important?
It allows each DNA strand to act as as template during DNA replication so that it can be copied perfectly.
It also means that DNA can be transcribed into a mRNA molecule.
What is genetic codes?
A sequence of bases
What is DNA made of?
Phosphate
Nitrogenous base ( A C G T)
Pentose sugar (deoxyribose)
What is RNA made of?
Phosphate
Pentose sugar (ribose)
Nitrogenous base (A C G U)
What does the bases in DNA stand for?
Adenine
Thymine
Cytosine
Guanine
What’s are DNA’s complimentary based?
A and T
C and G
What are 3 main functions of DNA
Cell division
Protein synthesis
DNA replication
What does DNA and RNA stand for?
Deoxyribonucleic acid
Ribonucleic acid
What is the function of RNA?
To transfer genetic information to the ribosome for protein synthesis
What are the characteristics of bacterium
0.5 um- 5 um
prokaryotic cell
What are the characteristics of fungus?
5um- 50um
Eukaryotic cell
What are the characteristics of protist?
1um-2mm
Eukaryotic cell
What are the characteristics of virus
20 nm - 350 nm
What does pathogen mean?
Microorganisms which are the causative agents of disease
What diseases can bacteria pathogens cause?
Chlamydia
Gonorrhoea
Tuberculosis
What diseases can virus pathogens cause?
Common cold
Mumps
Measles
What diseases can fungi pathogens cause?
Yeast infection
What diseases can prion pathogens cause?
CJD
What diseases can protist pathogens cause?
Malaria
What are 3 direct ways that pathogens can enter the body?
Sharing of needles
Unprotected sexual contact
Physical contact w an infection person or contaminated surface
What are 2 indirect ways pathogens can enter the body?
Vehicle transmission eg ingesting infected food or water
Being bitten by an infected vector eg insect bites
What are 3 ways that infectious diseases can spread amongst populations?
Inadequate sanitation
Lacy of social distancing due to dense population
Lack of accessible health promotion information
What is an antigen?
A substance that is recognised by the immune system as self or non self and stimulates an immune response.
What is an antibody?
A blood protein produced in response to and counteracting a specific antigen
What are 2 links between the antigen and the initiation of the body’s response to invasion of foreign substances?
Recognition of non self antigen leading to the initiation of an immune response.
Ability of the body to be able to recognise self and non self antigens.
What are 3 roles of non specific defences to protect the body from foreign substances.
Use of physical and chemical barriers
Inflammation
Phagocytosis
What are 2 roles of specific defences to protect the body from foreign substances?
Actions of the T cells
actions of the b cells
What is the role of T and B cells?
They trigger a stronger and more rapid immune response after encountering the same antigen.
What is injury?
Damage to the body caused by external forces.
How does the body respond to injury
Involuntary inflammation response
Proliferation phase
What is trauma?
An injury that has the potential to cause disability or death.
What are 6 ways the body reacts to trauma?
Involuntary inflammation response
Loss of organ function
Haemorrhaging
Multi organ failure
Proliferation phase
Bone structure deformity/damage/loss of structure
What is the role of MRI scanning in the detection and monitoring or traumas and injuries?
Uses strong magnetic fields and radio waves to generate detailed images of inside the body.
What are 2 considerations that should be taken into account before using MRI scans?
Patients medical history including implants containing magnetic metals.
Preparing the patient including removing all external metal objects.
What is epidemiology?
The study and analysis of the distribution and patterns of disease in population and why they occur.
What is incidence?
The occurrence of new cases of disease, injuries or other medical conditions over an specified period of time.
What is prevalence?
The proportion of a population with a disease or a particular condition at a specific point in time.
What is mortality?
The occurrence of death
What is a mortality rate?
The frequency of death in a population over a specific period of time.
What is morbidity?
The state of having a disease or medical condition.
What are 5 used of epidemiology?
Identify the causes of diesease
Determine the extent of the disease
Identify the trends and patterns of the incidence of the disease
Study the progression of disease
Develop public health policy and preventative measures
How does communication help prevent the the spread of disease?
Raising awareness of required behaviours through a range of mediums eg media campaigns
How does policies and systems help prevent the spread of disease?
Systematic changes to procedures, regulations or law to enforce required behaviours eg applying restrictions
How does educational programs help prevent the spread of disease?
It improves knowledge and empowers individuals to adapt their own behaviour
How does homeostasis contribute to maintaining a healthy body?
It’s maintains stability and function of the physiological systems and cells when there are changes to internal and external condition that would otherwise prevent enzymes from functioning normally
Topographical
Anatomical
Physiological
Topographical- by bodily region or system
Anatomical- by organ or tissue
Physiological- by function or effect
3 facts about the Alpha particle
.consists of 2 neutrons and 2 protons
.high ionising but low penetrating power
-range is 1 to 2 centimetres of air
3 facts about beta particles
.a high-speed electron ejected from the nucleus as the neutron turns to a proton
.medium ionising and perpetrating power
.range is approximately 15 centimetres of air
3 facts about gamma particles
.electromagnetic radiation from the nucleus
.low ionising and high penetrating power
.range is many kilometres of air
What is half life?
The time taken for half of the unstable nuclei in a sample to decay
What are the units for kilograms, meters and seconds?
Kilograms- mass
Meters- length
Seconds- time
What are 2 reasons why it is important to use significant figures?
Makes calculations with large or small numbers less cumbersome
Reduces the changes of error
What are enzymes?
Biological catalysts
What are proteins broken down by and what do they turn into?
Pepsin and trypsin
Amino acids
What are lipids broken down by and what do they turn into?
Lipase
Fatty acids
What are carbohydrates broken down by and what do they turn into?
Amalyse, sucrose,maltose and lactose
Sugars?
What does it mean when an enzyme denatures?
That the enzyme has changed shape
What breaks down maltose into glucose?
Maltase
What breaks down sucrose into glucose and fructose?
Sucrase
What breaks down lactose into glucose and galactose?
Lactase
Why cant sucrase break down maltose?
The substrate maltose doesn’t have a complimentary shape to the active site of sucrase so the bind won’t form an emzyme substrate complex
