Organelles Flashcards
Ribosomes
- small units that are not surrounded by a membrane and have two units
- SITES OF PROTEIN SYNTHESIS
Where are Ribosomes found?
- floating freely in cytosol
- bound to membrane of other organelles
- bound to nucleus
Peroxisomes
- contain enzymes chemicals produced by cellular reactions
- metabolize fatty acids
- synthesize phospholipids
Rough Endoplasmic Reticulum
- membrane enclosed sac that is studded with ribosomes.
- protein synthesis and modifies proteins made by ribosomes
Smooth ER
- lacks ribosomes
- lipid synthesis and detoxification reactions
Where does Golgi Apparatus receive proteins from?
Rough ER
Golgi Apparatus
Flattened sacs
-processes, modifies and sort products from vesicles sent by RER.
Lysosomes
-contain digestive enzymes that break down particles brought into the cells, old and worn out organelles or the cell itself
Centrioles
- composed of microtubules
- located in the centrosome
Nucleus
- directs the synthesis of proteins
- surrounded by the nuclear envelope which contains nuclear pores
Chromatin is and its contains?
- found within the nucleus
- a ball like mass of tightly coiled DNA and proteins, RNA and a nucleolus
Nuclear envelope
-double layer membrane that contains the nucleus
Nucleolus
- found within the chromatin which is in the nucleus
- contains Ribosomal RNA and site of ribosome synthesis
Phagocytes
immune cells
Diffusion
movement of a solute from an area of high concentration to low concentration
- passive process
- no energy required
Where does energy come from in difussion
concentration gradient
What increases rate of diffusion
- temperature
- particle size
- concentration gradient
Passive Transport
- Diffusion
- facilitated diffusion (carrier transport)
Active Transport
ATP Pumps
Osmosis
movement of solvent (water) from area of high solvent concentration to low solvent concentration
Hypotonic
Lower solute concentration than the cytosol
Cell Crenation
cell shrinks due to being placed in a hypertonic solution
Cell Lysis
cell swells and bursts when placed in hypotonic solution
Isotonic
same solute concentration on both sides of the membrane
4 Stages of Mitosis
- Prophase
- MetaPhase
- Anaphase
Cell Cycle - 4 Phases
G1, S phase, G2 and M phase (mitosis)
G1
growth phase
G2
second growth phase
S phase
DNA replication
Interphase consists of
G1, S and G2 phases
Prophase
- Nuclear envelope disintegrates
- DNA condenses
- mitotic spindle forms
Metaphase
Chromosomes line up at metaphase plate
-Spindle fibers (microtubules) attach to the chromosomes
Anaphase
The Chromatids separate and move towards opposite poles
In which phase does cytokinesis begin?
Anaphase
Telophase
- cleavage furrow pinches the cell into two identical daughter cells
- nuclear envelope reappears
- mitotic spindle becomes less visible
- cytokinesis completed
