Cell Biology Flashcards
Cell membrane
Cholesterol increases membrane fluidity
Cells are negative inside compared to outside 2/2 to Na/K ATPase 3na out 2K in
Na gradient used as cotransport of glucose, proteins and other
Tight junction
Desmosomes
Hemidesmosomes
Tight junction - cell to cell junctions creates impermeable membrane (epithelium)
Desmosomes- cell to cell anchor
hemidesmosomes – cell to extracellular matrix anchor
ABO blood type antigen
HLA type antigen
ABO blood type antigen - glycolipid on cell membrane
HLA type antigen - glycoprotein on cell membrane
WBC - have nuclear material (nucleus)
RBC and platelets do not have nuclear material
Cell Cycle
G1 SG2M
S (protein synthesis, chromosomal duplication)
G2 – check point, stops progression to M if issues with DNA
M = Mitosis and nucleus divides.
G1 - most variable, determines cycle length. Growth factors affect G1
Cells can go to G0 (quiescent) from G1
Prophase - centromere attachment, centriole and spindle formation
Metaphase - chromosome align
Anaphase - chromosome pull apart
Telophase - separate nucleus reforms
Transcription/ translation
Transcription - DNA used as template by RNA polymerase to synthesis of mRNA
Translation - mRNA used as template by ribosome to make proteins
Transcription factors - Bind DNA to transcribe genes
Steroids enter nucleus and act as a transcription factor
Purines
Pyrimidines
Purines - Guanine and adenine
Pyrimidines - cytosine, thymidine (Only DNA), uracil (only RNA)
Guanine forms 3 hydrogen bonds with cytosine
Adenine forms 2 hydrogen bonds with either thymidine or uracil
Cell Organelles
-Nucleus - double membrane, with the outer continuous with RER
-Nucleolus - inside nucleus, no membrane, Ribosomes made here
-Rough ER makes proteins that are exported.
-Smooth ER → lipid/ steroid synthesis, detoxifies drugs
-Golgi apparatus - modifies proteins with carbohydrates. Proteins then transferred to cell membrane → secreted or targeted to lysosomes
-Phagosomes - engulf large particles then fuse with lysosomes
-Endosomes - engulf SMALL particles and fuse with lysosomes
Glycolysis
Glycolysis - 1 glucose molecule makes 2 ATP and 2 pyruvate
Mitochondria – Where NADH/FADH is made. Krebs cycle
- Krebs (citric acid) cycle - 2 pyruvate to create NADH and FADH2 → these enter electron transport chain → leads to H+ gradient → creation of ATP by ATP synthase
1 glucose makes 36 ATP
Gluconeogenesis
- mechanism in which lactic acid (Cori cycle) and AAs (alanine #1), convert to glucose
- Used in times of starvation/stress
- Fat and lipids are not available for gluconeogenesis
Cori cycle
Cori cycle
Glucose is used and converted to lactate in muscle
Lactate then goes to liver and converts lactate back to pyruvate and then glucose via gluconeogenesis
Glucose transported back to muscle
Macrophages
Main source of TNF alpha and IL-1
IL-6
Increases hepatic acute phase proteins
IL-8
PMN chemotaxis and angiogenesis
IL-10
Anti-inflammatory response
TNF alpha
Cachexia, also increases adhesion molecules ICAM and SELECTIN
