Flashcards in Bacteria, Evolution, and Cells Deck (23):
What is the function of lysosome?
The lysosome functions to breakdown macromolecules in the cell. The pH is around 5 which is perfect for breaking down bonds.
Describe the the differences in the ribosomes of the cytoplasm and the ribosomes of the rER.
Ribosomes in the cytoplasm create proteins that mainly to stay in the cytoplasm. Ribosomes in the rER mainly create proteins to be transported out of the cell either to another location or on the cell membrane.
Describe the process by which proteins are transported out of the cell.
The protein is created on the rER, with a signal sequence located on the protein. The signal sequence directs the protein towards the lumen of the rER towards to Golgi App. The Golgi modifies the protein by adding various sugars then sends transport it to a secretory vesicle. The vesicle undergoes exocytosis to leave the cell.
What are the primary functions of the smooth ER?
1. lipid metabolism & storage
What is the function of the peroxisome?
Peroxisomes function to remove chemical toxins from the cell, especially hydrogen peroxide.
Describe the Mitochondria in relation to DNA.
The mitochondria has it's own circular DNA seperate from the DNA located in the nucleus. The mitochondria has it's own set of ribosomes. The DNA is passed down maternally.
Describe the structure of the mitochondria.
The mitochondria has two phospholipid bilayers. The outside layer and an inside layer. This leaves the matrix in the middle on the inside layer and the intermembrane space in-between the two outer & inner layers.
Describe the differences between eukaryotic & prokaryotic flagella.
Eukaryotic flagella are made from 9+2 microtubule config and undergo whip like action.
Prokaryotic flagella have a thin strand of flagella which rotates.
Describe the function of the microtubule.
The microtubule is the largest of the three parts of the cytoskeleton. Microtubules help with the movement of molecules within the cell. For example, microtubules help with the movement of secretory vesicles and also help with the movement of the mitotic spindle during mitosis.
How is the microtubule used structurally?
The microtubule is configured to form long filaments. There is a - and + microtubule. The microtubule grows away from the MTOC. 9 microtubule +2 lone microtubule configuration for flagella and cilia.
Describe the function of the microfilaments.
Microfilaments is another name for actin which is involved in the contraction of muscles. Microfilaments are also responsible for the cleavage during mitosis.
Describe the function of intermedia filaments.
Intermediate filaments function in support and rigidity-- not as dynamic as the microtubule or the microfilament.
What types of molecules can pass through the cell membrane easily?
Small, nonpolar molecules can easily pass through.
Water is very permeable through the cell membrane.
Describe passive transport
Passive transport is the movement of a molecule from a high concentration to an area of low concentration. If a protein is required to help facilitate the movement across the cell membrane then it is called facilitated diffusion.
Describe active transport
Active transport is the movement of a molecule from an area of low concentration to an area of high concentration, AGAINST the gradient, using ATP or secondary transport system.
Describe the G1 phase of the cell.
The cell just finished mitosis and is starting to grow. The functionality of the cell is starting and the process are being implemented. There is a checkpoint at the end of G1 to determine if it is ready for the next phase (S) or go to G0.
Longest cycle in the cell usually.
Describe the G0 phase of the cell
Non growing state of the cell.
Describe the S phase of the cell.
The S phase of the cell is the phase where DNA replication takes place in preparation for mitosis.
Describe the G2 phase of the cell.
G2 is getting ready for mitosis. Microtubules are getting ready for anaphase. Mitosis Promoting Factor is released, and when it's high enough, then the cell undergoes mitosis.
Describe what a tumor repressor is.
Deactivation of the cell stage checkpoint which follows for continued, unchecked growth.
Describe tight junctions
Tight junctions are water tight seals that prevent the movement of molecules in and out out the junction. Bladder.
Desmosomes join two cells at a single point. Typically found joining skin cells. Strongest binding.