CELL and the CELL CYCLE Flashcards
the basic unit of life and the
structural and functional building
block of all living organisms.
Cell
The CELL THEORY
- All living organisms are composed
of one or more cells - The cell is the basic unit of structure
and organization in organisms - Cells arise from pre-existing cells
is a thin,
flexible barrier that surrounds
the cell and separates its
internal components from the
external environment.
CELL MEMBRANE
• It controls the movement of
substances in and out of the
cell, maintaining its internal
environment.
CELL MEMBRANE
is a gel-like
substance that fills the cell
between the nucleus and the cell
membrane.
CYTOPLASM
• It contains various organelles and
is the site for many cellular
processes, including metabolic
reactions, protein synthesis, and
transport of molecules.
CYTOPLASM
Powerhouse of the cell
MITOCHONDRIA
They generate energy in the form
of adenosine triphosphate (ATP)
through a process called cellular
respiration.
MITOCHONDRIA
Is the primary energy source
used by cells to carry out their
functions.
ATP
a network of membranous
tubules and sacs that extends
throughout the cytoplasm.
ENDOPLASMIC RETICULUM
A type of ER which is covered
with ribosomes and involved in
protein synthesis
Rough ER
A type of ER which is involved in
lipid synthesis, detoxification,
and calcium storage.
Smooth ER
responsible for
modifying, sorting, and packaging
proteins and lipids into vesicles for
transport to their final destinations.
GOLGI APPARATUS
Golgi Apparatus is consists of flattened membranous
sacs called __________.
Cisternae
is a membrane-
bound organelle involved in the
process of exocytosis, which is the
release of substances from a cell.
SECRETORY VESICLES
are small
membrane-bound organelles
involved in various metabolic
processes.
PEROXISOME
They play a role in detoxification
reactions, breakdown of fatty
acids, and the synthesis of certain
lipids.
PEROXISOME
It consists of two
centrioles, which are cylindrical
structures composed of microtubules.
CENTROSOME
The centrosome is surrounded by a
protein-rich matrix called _________.
Pericentriolar material (PCM)
are membrane-bound
organelles that contain digestive
enzymes.
LYSOSOMES
They break down waste materials,
cellular debris, and foreign
substances that enter the cell.
LYSOSOMES
involved in cellular
recycling and the removal of
damaged organelles.
LYSOSOMES
are responsible for
protein synthesis.
RIBOSOMES
They can be found either free in the
cytoplasm or attached to the
endoplasmic reticulum.
RIBOSOMES
control center of the cell.
NUCLEUS
It contains the cell’s genetic
material, including DNA, which
carries the instructions for cell
growth, development, and
reproduction.
NUCLEUS
is a double
membrane that surrounds the
nucleus.
NUCLEAR ENVELOPE
It acts as a barrier, separating the
contents of the nucleus from the
cytoplasm.
NUCLEAR ENVELOPE
are present in the
nuclear envelope, allowing
selective passage of molecules
between the nucleus and
cytoplasm.
NUCLEAR PORES
is the gel-like
substance that fills the nucleus
NUCLEOPLASM
provides a medium for the
suspension of various components
within the nucleus.
NUCLEOPLASM
is a distinct region
within the nucleus involved in the
production and assembly of
ribosomes.
Nucleolus
refers to the complex of
DNA, proteins, and RNA found within
the nucleus.
CHROMATIN
• It undergoes various levels of
condensation and decondensation to
regulate gene expression.
CHROMATIN
primary component of a chromosome
DNA
are two identical
copies of a chromosome that are held together
by a region called the centromere.
Chromatids
Is a specialized region of a chromosome where the two
chromatids are attached. It is responsible for ensuring proper separation of chromatids during cell division.
Centromere
are protective structures
located at the ends of chromosomes. They
consist of repetitive DNA sequences and play a crucial role in preserving the integrity and
stability of chromosomes
Telomeres
is the series of events that
take place in a cell leading to
duplication of its DNA and
division of cytoplasm &
organelles to produce daughter
cells.
Cell Cycle
is a critical stage in the
cell cycle that occurs between cell
divisions.
Interphase
It represents the period when the
cell is not actively dividing but is
engaged in various metabolic
activities and preparing for cell
division.
Interphase
3 Subphases of Interphase
- G1 phase
- S phase
- G2 phase
During this phase, the cell grows
in size, synthesizes proteins, and
carries out its normal functions.
G1 phase
It is a period of intense metabolic
activity, and the cell prepares for
DNA replication.
G1 phase
A phase where the cell undergoes
DNA replication or synthesis.
S phase
During this phase, the cell
continues to grow, synthesize
proteins, and prepare for cell
division.
G2 phase
serves as a
checkpoint to ensure that the cell
is ready for mitosis.
G2 phase
• It is a crucial part of the cell cycle
where the parent cell divides into
two daughter cells.
M phase
4 main phases of M phase
- Prophase
- Metaphase
- Anaphase
- Telophase followed by cytokinesis
During this phase the chromatin
condenses into visible
chromosomes.
• The nuclear membrane
disassembles, and the mitotic
spindle apparatus begins to form.
• Centrioles move to opposite poles
of the cell, and spindle fibers
extend from them.
Prophase
the condensed
chromosomes align along the
equatorial plate or metaphase
plate, an imaginary plane at the
center of the cell.
• The spindle fibers attach to the
kinetochores located at the
centromere region of each
chromosome.
Metaphase
is characterized by the
separation of sister chromatids. The
spindle fibers contract, pulling the
sister chromatids apart toward
opposite poles of the cell.
• This ensures that each daughter
cell receives an identical set of
chromosomes.
Anaphase
the separated
chromosomes reach the opposite
poles of the cell.
• They start to decondense, and new
nuclear membranes form around
each set of chromosomes.
• The mitotic spindle apparatus
disassembles, and the cell
prepares for cytokinesis.
Telophase
is the final stage of
the M phase and involves the
physical division of the
cytoplasm, organelles, and
cellular components to form two
daughter cells.
Cytokinesis
is a specialized type of cell
division that occurs in sexually
reproducing organisms.
• It involves the production of gametes
(sperm and eggs) with half the number
of chromosomes as the parent cell.
Meiosis
it ensures the
proper distribution of genetic material
and contributes to genetic diversity in
offspring.
Meiosis
the
chromosomes condense,
and homologous
chromosomes pair up to form
structures called tetrads.
• Crossing over occurs
between non
-sister
chromatids of homologous
chromosomes, resulting in
the exchange of genetic
material and genetic
recombination.
Prophase I
Tetrads align at the
metaphase plate, an
imaginary plane in the center
of the cell.
• Each tetrad attaches to
spindle fibers originating
from opposite poles of the
cell.
• The orientation of the tetrads
is random, contributing to
genetic diversity.
Metaphase I
The homologous
chromosomes separate and
move to opposite poles of the
cell, guided by the spindle
fibers.
Anaphase I
The chromosomes reach the
poles of the cell, and the cell
divides into two daughter cells.
• nuclear envelopes form around
each set of chromosomes.
• Each daughter cell contains
only one set of chromosomes
but with duplicated chromatids.
Telophase I and Cytokinesis I
The nuclear envelope breaks
down again, and
chromosomes recondense.
• A new spindle apparatus
forms in each daughter cell.
Prophase II
The duplicated chromosomes
align at the metaphase plate,
similar to metaphase in
mitosis.
• Spindle fibers attach to the
centromeres of sister
chromatids.
Metaphase II
