SFBH S1 Flashcards
Define Health
a state of complete physical, mental and social wellbeing and not merely the absence of disease or illness (WHO)
Define Disease
impaired physical, emotional and/or mental function * disturbance of homeostasis
Why is Disease and Health hard to define?
- Very broad terms
- Every organism responds differently to a disease and fluctuations of homeostasis
- Health can vary daily and because of aging
- Everyone has different idea of what their quality of life should be
- Example: Person carrying the infectious pathogen HIV may be ‘healthy’ if the symptoms of the disease AIDS has not appeared
- Because you have a cold, does that mean you are unhealthy?
How does the function of genes Assist in the maintenance of health?
- To ensure that the correct proteins are produced to enable cellular processes to continue
- Gene expression = proper function is essential to maintain good health
- If genes faulty, and polypeptides and proteins are faulty, cell processes/structures may be abnormal and disease can result
- Growth and healing of tissue dependent on protein metabolism = controlled by genes
How does the function of Mitosis Assist in the maintenance of health?
- Cell division that allows normal growth and repair
- If process goes wrong = maybe cancer = occurs when cells rapidly divide and do not carry out cell differentiation and specialisation
- When this happens = tumour grows making organism unhealthy
How does the function of cell differentiation and specialisation assist in the maintenance of health?
• Cell Differentiation: change from unspecialized cell to specialised cell
= Become specialised for different functions
= Undifferentiated cells form tumours
• Cell Specialisation: cells have differentiated to perform particular function
= Allows cells to develop structure to best perform specific functions
= e.g. to prevent entry of pathogen
Gene expression….
gene information used in the production of a protein or other gene product
Steps of gene expression.
- ‘Switching on’ segment of DNA to produce a polypeptide
- Changing polypeptide into required protein
- Making protein become either:
o A component of cytoplasm
o OR an enzyme and control production of other cells
In relation to gene expression and the maintenance and repair of body tissues what are constitutive genes and when are they expressed?
ALWAYS EXPRESSED genes that maintain normal body functions
E.g. genes that code for digestion enzymes (amylase) must be constantly expressed to produce saliva when needed
In relation to gene expression and the maintenance and repair of body tissues what are faculative genes and when are they expressed?
only EXPRESSED WHEN NEEDED
• Example: Regenerating family of proteins that are only largely expressed in bowel disease
o Genes are expressed to assist in the maintenance and repair of body tissues
• When there are sufficient cells & organelles, mitosis allows cells to divide which equals?
occurrence of cell differentiation and separation
Specialised cells…
can’t divide. e.g nerve cells, as they are not easily replaced.
Use available evidence to analyse the links between gene expression and maintenance and repair of body tissues example shown with breast cancer… explain.
• Genetic
• ‘Basal-like’ cancer = aggressive, difficult to control and harder to treat
• Type caused by mutation of BRCA1 gene
Put women at much higher risk of developing particular form of BC
Increases risk of developing BC by 85%
• BRCA1 gene:
Tumour suppressor gene: code for proteins which slow down or stop mitosis
- Cause cell death if uncontrolled increase in cells
Located on chromosome 17
• PTEN gene:
Tumour suppressor gene: regulates cell cycle and prevents excessive proliferation of cells
• If damage to PTEN gene = repaired by BRCA1 gene proteins PTEN gene would be expressed properly and cell division would be controlled
• Mutations to BRCA1 gene = proteins necessary to repair PTEN not produced = PTEN not repaired and not expressed = uncontrolled cell cycle = formation of tumours
