Biology Flashcards
What are the points of the cell theory?
- all living things are composed of cells
- the cell is the basic functional unit of life
- all cells come from pre-existing cells
- THE CHEMICAL REACTIONS OF LIFE TAKE PLACE INSIDE THE CELL
- CELLS CARRY GENETIC INFORMATION IN THE FORM OF DNA, WHICH IS PASSED FROM PARENT CELL TO DAUGHTER CELL
Function of the Golgi Apparatus
receives contents from the SER and then modifies them, repackages them into vesicles, and sends them to the cell surface for exocytosis
What are centrioles composed of?
microtubules
how do materials (not organelles) circulate in the cell?
Brownian movement-kinetic energy/movement sends small suspended particles circulating through a cell
Cyclosis or cytoplasmic streaming-circular motion of cytoplasm sends small particles throughout the cell
ER-forms a network of channels throughout the cytoplasm and provides a direct continuous passageway from the plasma membrane to the nuclear membrane
lysosomes
o Contain hydrolytic enzymes
♣ Means the cleavage of chemical bonds by the addition of water
• Without water, hydrolytic enzymes cannot cleave bonds—therefore lysosomes cannot do their job
o Break down materials ingested by the cell
o An injured/dying cell may undergo autolysis by rupturing lysosomes
This happens in a very controlled manner
what is the cytoskeleton composed of?
♣ Microtubules
• Hollow rods made up of polymerized tubulin
• Provide the framework for organelle movement within the cell
• Cilia and flagella are composed of microtubules in a specialized arrangement
o Involved in cell motility and cytoplasmic movement
♣ Microfilaments
• Made up of solid rods of actin
o Important in cell movement and support
• Muscle contraction occurs from interactions of myosin and actin
• Move material across the plasma membrane in the contraction phase of cell division and during amoeboid movement
♣ Intermediate filaments
o Cytoskeleton composed of all the types of structural proteins
