The Cell (PPT based) Part III Flashcards
pair of cylindrical rods (0.2 µm wide and 0.5 µm long) oriented at right angles to one another
CENTRIOLES
located in the centrosome (cell center)
CENTRIOLES
direct the formation of spindle fiber during cell division forms the bases of cilia and flagella (mother centriole)
CENTRIOLES
lifeless accumulations of material
INCLUSIONS
not metabolically active
INCLUSIONS
glycogen, lipid droplets, lipofuscin
INCLUSIONS
microtubules, microfilaments, intermediate filaments, microtrabecular lattice
CYTOSKELETON
structural framework within the cytosol
CYTOSKELETON
functions in:
maintaining cell shape by providing cellular support
CYTOSKELETON
functions in:
stabilizing cell attachments
CYTOSKELETON
functions in:
facilitating endocytosis and exocytosis
CYTOSKELETON
functions in:
facilitating endocytosis and exocytosis
CYTOSKELETON
functions in:
promoting cell motility
CYTOSKELETON
Nucleus includes:
Nuclear envelope
Nucleoplasm
Nucleolus
Chromatin
control various activities of the cell essential for reproduction and heredity transmission
NUCLEUS
contains genetic apparatus encoded in the deoxyribonucleic acid (DNA) of chromosomes
NUCLEUS
directs protein synthesis in the cytoplasm via:
ribosomal RNA (rRNA)
messenger RNA (mRNA)
transfer RNA (tRNA)
NUCLEUS
surrounds the nuclear material
NUCLEAR ENVELOPE
consists of two parallel membranes separated from each other by a narrow perinuclear cisterna
NUCLEAR ENVELOPE
perforated at intervals by openings called nuclear pores
NUCLEAR ENVELOPE
well-defined nuclear inclusion (sometimes > one)
NUCLEOLUS
eccentrically placed within the nucleus
NUCLEOLUS
not membrane-bound
NUCLEOLUS
present in cells actively synthesizing protein
NUCLEOLUS
generally detectable only when cell is in interphase
NUCLEOLUS
involve in synthesis of rRNA and its assembly into precursors of ribosomes
NUCLEOLUS
portion of the protoplasm that is surrounded by the nuclear envelope
NUCLEOPLASM
consists of a matrix and various types of particles
NUCLEOPLASM
double-stranded DNA complexed with histones and acidic proteins
CHROMATIN
responsible for RNA synthesis
CHROMATIN
What are the 2 forms of chromatin?
heterochromatin and euchromatin
heterochromatin and euchromatin:
light microscope: basophilic clumps of nucleoprotein
electron microscope: dense granular clumps
HETEROCHROMATIN
concentrated at periphery of nucleus, around the nucleolus and scattered throughout the nucleoplasm
HETEROCHROMATIN
heterochromatin and euchromatin:
transcriptionally inactive
HETEROCHROMATIN
heterochromatin and euchromatin:
light microscope: lightly stained dispersed region of the nucleus
electron microscope: electron-lucent regions among heterochromatin
EUCHROMATIN
heterochromatin and euchromatin:
transcriptionally active
EUCHROMATIN
What are the 2 major periods of cell cycle?
- Interphase – interval
- Mitosis (M phase) – period of cell division
longer than M phase
Interphase
cell doubles in size and DNA content
Interphase
What are the 3 separate phases of Interphase?
G1, S and G2
the gap phase just after mitosis
G1 phase
when certain “trigger proteins” are synthesized enabling the cell to reach a threshold (restriction point) and proceed to the S phase
G1 phase
lasts from a few hours to several days
G1 phase
cell growth and protein synthesis occur, restoring daughter cells to normal volume and size
G1 phase
also known as synthetic phase
S phase
DNA replication and protein synthesis occur
S phase
resulting in duplication of the chromosomes
S phase
period when centrioles are self-duplicated
S phase
lasts 8-12 hours in most cells
S phase
