Genetics and Cellular Function Flashcards
DNA Function
Serves as a code for protein synthesis. (blueprints)
Gene
Sequence of DNA nucleotides that codes for one polypeptide
Genome
All the genes of one person.
How many genes do humans have?
35,000
RNA structure and function
Much smaller than DNA. Essential function is to interpret DNA code and to direct protein synthesis in the cytoplasm
How are our hormones released?
The growth hormone hits DNA and it sends RNA out to tell other enzymes to make the protein.
Errors and Mutations
Changes in DNA structure due to replication errors or environmental factors. Cancer has mutant cells that stay alive and reproduce at dramatic rates.
When do cells divide? 4
-Have enough cytoplasm for 2 daughter cells
DNA replicated
-Adequate supply of nutrients
-Growth factor stimulation
-Open space in tissue due to neighboring cell death
When do cells stop dividing? 2
- Loss of growth factors or nutrients
- Contact inhibition
Heredity
Transmission of genetic characteristics from parent to offspring
How many chromosomes do we get from our parents?
23 from mom and 23 from dad
How many chromosomes do sperms and eggs have?
23
Tumors
(neoplasms)Abnormal growth, when cells multiply faster than they die. Oncology is the study of tumors
Benign (tumor)
Will not cause any effect, except for putting pressure on other organs
Malignant
Unencapsulated, fast growing, metastatic (causes 90% of cancer deaths) They can Displaces normal tissue, organ function deteriorates. Block vital passageways. Diverts nutrients from healthy tissues
Carcinogens
A cause of cancer. Estimates of 60 - 70% of cancers from environmental agents. It can be chemical, radiation, or viruses.
Mutagens
Trigger gene mutations. The cell may die, be destroyed by immune system or produce a tumor
Defenses against mutagens 4
Scavenger cells-remove them before they cause genetic damage
Peroxisomes-neutralize nitrites, free radicals and oxidizing agents
Nuclear enzymes-repair DNA
Tumor necrosis factor (TNF) from macrophages and certain WBCs destroys tumors (white bloods cells attack the tumor
Oncogenes
Genes from parents that make you more likely to get cancer
Tumor suppressor genes
Genes that make you less likely to have cancer. If damaged you are more likely to trigger cancer.
