Patho Week 1 Flashcards
Chromosomes
Organized packages of DNA in the nucleus. 23 pairs of chromosomes, 22 are autosomes, 2 are sex chromosomes.
DNA
In chromosomes
Genes
Functional parts of DNA
Somatic Cells
Cells, organs, tissues 46 chromosomes in 23 pairs Diploid Formed by mitosis Autosomes - 22 pairs are in autosomes, one pair of sex chromosomes
Gametes
Sperm and ovum
23 chromosomes
Haploid
Formed by meiosis
DNA nucleotides
A-T
C-G
RNA nucleotides
U-A
C-G
Helicase
Enzyme that breaks down hydrogen bonds between nucleotides leaving sing strands. “Unzipper”
Polymerase
Enzyme that travels on a single strand of DNA and adds the correct nucleotides. Proofreads to increase the accuracy of DNA replication
Mutations
When the consistent pairing does not happen correctly.
Mitosis
Replication of somatic cells.
Central Dogma
Genes direct the synthesis of proteins.
- Transcription
- Translation
Transcription
mRNA is synthesized from single stranded DNA template. Similar to replication, U replaces T. Makes mRNA, which leaves the nucleus and travels to cytoplasm.
Translation
mRna interacts w/ribosomes. Ribosomes read the sequence and build codons (units of 3). Multiple codons together leads to amino acids, which are the building blocks of proteins.
Protein functions (5)
Structure Antibodies Enzymes Messengers Transport/Storage
Protein - Structure
Provides support for cells. (Elastin, collagen)
Protein - Antibodies
Bind to specific foreign particles (viruses & bacteria) to help protect the body. (immunotherapy aka immunoglobulin G)
Protein - Enzymes
Carry out almost all the chemical reactions that take place in cells. Assist with replication, transcription, translation. (Lactase)
Protein - Messengers
Transmit signals to coordinate biological processes. (Oxytocin, insulin)
Transport/Storage
Bind and carry atoms and small molecules within cells and throughout the body. (hemoglobin)
Modes of cell signaling (3, fastest to slowest)
- Direct contact via receptors (paracrine, autocrine)
- Signal protein moves from one cell to another via interstitial fluid (must be relatively close, ie neurotransmitter)
- Signal protein moves from one cell to another via the bloodstream (further apart, hormonal)
3 types of cell surface receptor proteins
- Ion channel
- Enzyme-linked receptor
- G-protein linked receptor
Ligand-gated ion channel
Receptor is on the cell surface. Ligand binds to the receptor and opens and closes so the ion can pass through. (Nicotinic receptors, Gaba receptors)
G-protein coupled receptors
“Second messenger”. Attaches, reactions to separate molecules, second messenger activated. The second messenger does the work in the cell, the G-protein receptor is on the cell membrane.