biology chapter 5 Flashcards
what is health?
Health is a state of complete physical, mental and social wellbeing not merely the
absence of disease or infirmity.
what are pathogens
they are bacteria, viruses or parasites which can use or destroy our body cells for their own survival, while causing diseases that make a person feel ill.
- For many micro-organisms, including pathogens, inside the human body is the perfect environment: normal body temperature (between 36 and 37’C)and the dissolved substances in our blood and cells create an ideal habitat
for them to carry out all of their life functions
Why do we fee L as a result of having these pathoqenic micro-organisms growing inside us?
Some of the waste materials that pathogenic bacteria produce and ther release rnlo or,tr body are toxtns sma I amounts of ‘poison’that enter body cel1s, damaqrng or ki lnq our healthy body cells, and rraking us fee unwe I rn the process
How do viruses that do not contain all the components to reproduce, reproduce?
v ruses are not capable of reproduc ng on their own; nstead, they must enter nto other healthy ce ls and take over the reproductive
mechan sms of those cells When th s happens, the hea thy host cel s use their own ce lu ar components to assemble new viruses Soon, the host ce ls fr I wrth the newly assemb ed viruses, rnt the host ce no longer can support its own needs for survival. At thrs po nt, the host ce ls br-rrst open, releas ng all of the newly formed v ruses.
Explain the active virus life cycle?
STEP 1: Attachment
The phage attach to specific receptors on the cell wall of E. Coli.
STEP 2: Penetration
Following attacment, phage DNA is injected into the bacterial cell, leaving the phage coat outside
.Step 3: Transcription
Phage DNA is transcribed, producing phage mRNA, which is translated to phage proteins.
Step 4: Replication of Phage DNA and Synthesis of Proteins
Phage coat proteins, other protein components, and DNA are produced separately. Host DNA degraded.
Step 5: Assembly
Phage components are assembled into mutated virions.
Step 6: Release
The bacterial cell lyses and releases many infective phage.
what is the explanation for some of the symptoms we feel when sick
Other symptoms when you are ill come from your body’s defence system, called the immune system, in its attempt to regain the balance of healthy body cells to pathogenic cells - a balance which the body begins to lose when
the pathogens start to rapidly grow and reproduce.
what is the role of sticky mucus and phlegm
The sticky mucus and phlegm that the cells in your nose and lungs produce are your body’s way of trapping pathogens before they fully enter the body. When you sneeze, cough or blow your nose, all of those pathogens that were caught by the mucus or phlegm end up in the tissue or air, instead of in your body. ln addition, the phlegm and mucus our body produces contain antibodies, which are molecules produced by specialized cells, called white blood cells, in
the immune system. ln response and in order to fight off invading pathogens, your body produces more white blood cells, which, in turn, produce more antibodies.
what is the function of white blood cells
- this increased level of white blood cell productron is an important strategy to protect you in the future, because some of the white blood cells are known as’memory cells’. Their job is to circulate in your body,
ready to immediately produce antibodies in the case of a future infection. - the phlegm and mucus our body produces contain antibodies, which are molecules produced by specialized cells, called white blood cells, in
the immune system. ln response and in order to fight off invading pathogens, your body produces more white blood cells, which, in turn, produce more antibodies.
what is the role of diarrhoea or vomit
it is your body trying to make itself less welcoming to pathogens because your digestive system becomes more acidic. ln addition, you are physically and actively removing the pathogenic micro-organisms from your body.
what are antibiotics
- are substances that damage, destroy or kill certain types of cells; specifically, antibiotics target certain types of bacterial cells.
- Many antibiotics are found in nature; for example the popular antibiotic penicillin originates from a type of mould.
- can be effective only in treating diseases caused by bacterial infections. This means that. if a parasite or
virus causes a disease, antibiotics will not be an effective treatment for eliminating the pathogens that cause the disease. ln these types of parasitic or viral infections, doctors may prescribe medicines that help to reduce the symptoms of the infection so you feel better while your body is trying to fight the disease.
what is infection
Infection occurs when harmful microorganisms—such as bacteria, viruses, fungi, or parasites—enter the body, multiply, and cause illness or disease. These microorganisms can invade tissues, disrupt normal bodily functions, and trigger an immune response.
Types of Infections:
Bacterial Infections –
Viral Infections –
Fungal Infections –
Parasitic Infections –
what happens when we have an infection?
