A Healthy Diet Flashcards
What should a health diet be?
It should contain. The right balance of the different foods you need and the right amount of energy
What are all the food types?
- carbohydrates
- fats
- proteins
- vitamin
- mineral ions
- fibers
- water
What do fibres help do?
They help the digestive system
What does water do in the body
It transports dissolved substances
What happens if you fail to maintain a balanced diet
You will become malnourished
How can you maintain body weight
There needs to be a balance between energy intake and energy used up
Over a long period of time what happens if:
Energy intake is bigger than energy used
You will become overweight
Over a long period of time what happens if:
Energy intake is less than energy used
You will become underweight
Why does a growing teenager need more energy than elderly people
Because they need energy to create new tissues and bones
Why do pregnant women need more energy
Because they use up extra energy as they are also supplying a growing baby
What is your metabolic rate
It is the rate of the chemical reactions in your cells
Who can you change your metabolic rate
- exercise more, which uses up more energy during and after the exercise
- increasing the proportion of molecule compared to the fat in your body as you have a greater percentage of metabolically active cells
- as men generally have a higher muscle to ration than women, gender also affects the metabolic rate
- in cold climates, the metabolic rate rises to use up more energy just to remain body temperature
- various other genetic components may also effect metabolic rate, so inherited factors from your parents will also pay a part
What happens if more energy is taken in than is used
The excess is stored as fat
Obese cannot kill you but what can it do
It leads to diseases which will then kill you
What health problems can overweight or obese cause
Arthritis (osteo) caused by excess weight on joints
Diabetes (type 2) where the blood sugar can no longer be controlled
High blood pressure
Heart disease
What is cholesterol
It is a waxy fat molecule
What is cholesterol essential for
It is essential in the body for producing cell membranes and some hormones
How many types of cholesterol is there
2
What happens if you have to much of the bad cholesterol in your body
It can collect in the walls of your arteries and lead to heart disease
How can you rise the quantity of bad cholesterol in your blood
By eating lots of food with fat
How can you reduce the chance of this dangerous cholesterol building up in your arteries and why does it do this
By exercising because it triggers a rise in the healthy type of cholesterol and a drop in the harmful form
What is useful when you are investigating the properties of bacteria
To grow a large number
Why do we place bacteria Ina culture medium
Because it contains the nutrients required for them to grow
Why is it essential to use effective aseptic technique when preparing cultures of bacteria
To ensure that you only grow the bacteria that you want
What can contamination lead to when growing bacteria
It could lead to dangerous pathogens to grow instead
What are mutations
Changes in the DNA
What can mutation in the desired bacteria lead to
Dangerous strains being formed
Uncontaminated cultures of micro organisms are requires for investigating the action of disinfectants and antibiotics. Name all 5 steps in growing bacteria:
Step1: sterilise the loop by passing it through a Bunsen flame
Step 2: open the broth culture and dip the loop in
Step 3: inoculate the agar plate by streaking the loop across it’s surfaces
Step 4: try not to life the lied too much or touch the desk
Step 5: culture plates at 25oC over the weekend
Why do we never culture at a high temperature than 25oC
Because we don’t want to grow any pathogens the could be harmful to us (37oC)
What is a pathogen
It is a microorganism that causes diseases
Eg. Bacteria and viruses
What are bacteria and how do they reproduce?
They are small, single-celled organisms that reproduce rapidly
They reproduce very rapidly in our body and my produce poisons which make us feel ill.
What two types of bacteria are there
Some are harmless or actually good for us
Others release harmful toxins that damage are cells
What are viruses?
They’re even smaller than bacteria
How do viruses reproduce?
They reproduce very rapidly in our body and may produce toxins which make use feel ill.
By entering our cells and taking over them. This often damages or destroys the cell in the process.
Why do we feel ill?
It is either due to the damage caused by the pathogens themselves or it is due to the body’s own defence mechanism response to the infection
What have all existing pathogens evolved to do?
Spread from one person to another
Name the ways which pathogens travel from one place to another
Direct contact
Droplet infection
Contaminated food and drinks
Through a break in the skin
How do pathogens travel from one person to another through direct contact?
Skin to skin transfer occurs in diseases like impetigo and some sexually transmitted diseases
How do pathogens travel from one person to another through droplet infection?
Tiny drop of liquids containing pathogens are expelled when you cough, sneeze or talk. They can then me breathed in by others who can catch the disease
How do pathogens travel from one person to another through contaminated food and drinks?
Uncooked food or water contaminated with sewage can transfer pathogens like salmonella or cholera
How do pathogens travel from one person to another through a break in the skin?
The skin is the largest organ in the body and one of its main functions is to act as a barrier to prevent pathogens from entering the body
Give examples of how pathogens travel from one person to another through a break in the skin
Cuts, burns, needle punctures and insect bits
If you have a cut what does the skin do to prevent pathogens from entering the body?
It forms scabs
What do the lungs have the help get rid of pathogens?
It contains sticky mucus which traps the pathogens invading the breathing tubes, which can the be moved out and swallowed
What barrier does the stomach have to get ride of pathogens?
It has acids which destroys most of the pathogens which you swallow
What types of cell forms part of the immune system?
The white blood cells
White blood cells defend you in three main ways, which are…
Ingesting pathogens-destroys them with chemicals and enzymes are contained within the cells
Producing antibodies-which produces specifically for each pathogen. These bind to the bacteria or virus and destroys it. Once you have made it once, you can make it again quickly to stop you getting sick again.
Producing antitoxins, which counteract the toxins released by the pathogens
What do some drugs like aspirins and paracetamol do?
They treat the symptoms of an infection by reducing pain and inflammation. But have no affect on the pathogens itself
Why are antibiotics like penicillin better than some drugs like aspirins?
Because they kill bacteria without harming our own cells
What is the negative side of antibiotics ?
They have no effect on viruses as they reproduce inside of our cells
What do antibiotics have to be incredibly successful at ?
In reducing death from infectious diseases
Why is it bad that bacteria reproduce in such large numbers?
Natural selection as allowing them to gradually develop resistance against our drugs
What will it mean that mutations as the bacteria reproduce ?
That some will have different genetic make-up, and therefore different characteristics than others
What will happen if we use antibiotics that will kill off those bacteria that are susceptible to that drug ?
It leave those behind that are resistant to it (survival of the fittest), the population of resistant strain increases
What will happen to the few resistant bacteria which are left behind?
They will reproduce to form a whole new colony which cannot be harmed by that antibiotic
What will happen if other antibiotics are used to cure the new colony which has formed and what is it called?
The process will repeat itself and lead to the formation of multiple-resistant bacteria
This is call natural selection
Give and example of when multiple-resistant bacteria has occurred ?
MRSA (Methicillin Resistant Staphylococcus Aureus), It’s very dangerous because it’s a strain of bacterium that is resistant to most antibiotics
Why are new pathogens emerging all the time?
Due to mutations
Why is it bad the there are new pathogens emerging all the time?
It means the your immune system has to meet them for the first time making you feel ill from similar pathogens regularly
Eg cold or flue viruses
Also occasionally very dangerous and infectious strains appear
What is is called when stain causes a large outbreak of the disease in one country?
Epidemic
What is is called when stain causes to strap across several countries ?
Pandemic
Who can people become immune against a disease?
Trigger by introducing small quantities of dead or inactive forms of the pathogen into the body (vaccination). Vaccines stimulate the white blood cells to produce antibodies that destroy the pathogens. This makes the person immune to future infections by the microorganism. The body can respond by rapidly making the correct antibody, in the same way as if the person had previously had the disease.
Why MRSA causing so many problems in hospitals?
Because it is resistant to antibiotics this means a patient with it can not be treated and so it is passed on
Vaccines stimulate white blood cells to produce……………………….
Antibodies
What are carbonates, fats and proteins used by the body for?
To release energy and to build up cells
What are mineral ions and vitamins needed for?
They are needed in small amounts for healthy bodies functioning of the body
What is malnourished?
It is when a person does not have a balanced diet
What may an unbalanced diet lead to?
Overweight
Underweight
Deficiency diseases or conditions such as type 2 diabetes
How does a person lose mass?
When the energy content of food taken in is less than the amount of energy expended by the body.
What does exercise increase?
The amount of energy expended from the body
The rate in which all chemical reactions in the cells of the body are carried out (the metabolic rate) varies with…
The amount of activity you do and the proportion of muscle to fat in your body.
What may inherited factors affect?
Our metabolic rate
Our health-e.g. Cholesterol levels
What type of people are regularly healthier?
Those who exercise regularly
What does the immune system produce?
It produces specific antibodies to kill a particular pathogen. This leads to immunity from that pathogen. In some cases, dead or inactive pathogens simulate antibody production. Is a large proportion of the population is immune to a pathogen, the spread of the pathogen is very much reduced.
What did Semmelweis recognises?
The importance of hand-washing in the prevention of spreading some infectious diseases. By insisting that doctors washed their hands before examining patients, he greatly reduced the number of deaths from infectious diseases in his hospital.
What do medicines, such as painkillers do?
They help to relieve the symptoms of infectious disease, but do not kill the pathogens.
What can and can’t antibiotics do?
Antibiotics, including penicillin, are medicines that help cure bacterial diseases by killing infectious bacteria inside the body.
Antibiotics cannot be used to kill viral pathogens, which live and reproduce inside cells.
It is important that specific bacteria should be treated by specific antibiotics
Positive about antibiotics…
They greatly reduce deaths from infectious bacterial diseases
What does an overdoes or inappropriate use of bacteria lead to?
An increase in the rate of development of antibiotic resistant strains of bacteria
Many strains of bacteria, including MRSA, have developed restrains to antibiotics as a result of…
Natural selection
What is the result of mutations of pathogens as the they produce new strains?
Antibiotic and vaccines may no longer be effective against a new resist at strain of the pathogen. The new strain will then spread rapidly because people are not immune to it and there is no effective treatment.
Nowadays what are antibiotics used for?
To treat non-serious infections, such as mild throat infections, so that the rate of development of resistant strains is slowed down.
In school and collage laboratories, cultures should be incubated at a maximum of what temperature and why?
25oC
This greatly reduces the likelihood of growth of pathogens that might be harmful to humans
Industries they use a higher temperature when producing cultures, why?
Because this will allow them to grow more rapidly.
