ABSITE Review - Cell Biology Flashcards
What are desmosomes and hemidesmosomes?
Adhesion Molecules that anchor cells
What are tight junctions?
Cell-cell occluding junctions that form an impermeable barrier
What are gap junctions?
They allow communication between cells (conexin)
What is the order of the cell cycle?
G1 –> S (protein synthesis, chromosomal duplication) –> G2 –> M (mitosis, nucleus divides)
What part of the cell cycle determines the cell cycle lenght?
G1 because is the most variable.
In which part of the cell cycle, growth factors affect?
G1
What are the steps of mitosis?
- Prophase - centromere attachement, spindle formation, nucleus disappears
- Metaphase - Chromosome aligment
- Anaphase - Chromosomes pulled apart
- Telophase - Separate nucleus reforms around each set of chromosomes
How is the nucleus membrane?
Double and outer membrane is continuous with rough endoplasmic reticulum
Where are the ribosomes made?
Nucleolus which has no membrane
What occurs during transcription?
DNA strand is used as a template by RNA polymerase for synthesis of an mRNA strand
How the steroid hormones act as a transcription factor?
They bind a receptor in the cytoplasm then enter the nucleus
How the thyroid hormones act as a transcription factor?
They bind a receptor in the nucleus
Name the purines
Guanine and Adenine
Name the pyrimidines
Cytosine, Thymidine (only in DNA) and uracil (only in RNA)
Describe the the hydrogen bonds between the purines and pyrimidines
Guanine forms a hydrogen bond with cytosine
Adenine forms 2 hydrogen bonds with either thymidine or uracil
What occurs during translation?
mRNA is used as a template by ribosomes for the symthesis of proteins
Glycolysis produces …
1 glucose = 2 ATP + 2 pyruvate molecules
How many membranes has the mitochondria?
2 membranes and the Kreb cycle occurs in inner matrix
Kreb cycle produces …
2 pyruvate = NADH and FADH2
Electron transport chain produces …
34 ATP
How many ATPs are produced from 1 glucose molecule?
36
What is gluconeogenesis?
Mechanism by which lactic acid (Cori cycle) and amino acids are converted to glucose
Where the synthesis of the proteins that are exported occur?
Rough endoplasmic reticulum
Where the synthesis of lipids/steroids or drug detoxification occurs?
Smooth endoplasmic reticulum
What is the function of the Golgi apparatus?
Modifies proteins with carbohydrates and then trasnport them to the cellular membrane where they are secreted or targeted to lysosomes
What is myosin?
Thick filaments, uses ATP to slide along actin to cause muscle contraction
What is actin?
Thin filaments
Where are microtubules found?
Cilia, neuronal axons, centriole and mitotic spindles
