Cell and Molecular biology Flashcards
(63 cards)
All organisms are composed of one or more cells.
- New cells come from pre-existing cells; lifeforms today have descended
in unbroken continuity from the first primitive cells that arose on
earth more than 3.5 billion years ago.
- Hereditary information passed from parent cell to daughter cells.
- The fundamental biochemical reactions of life take place within cells
Modern cell theory
These are the basic unit of life.
Cells
- It is the scientific study of cells, its structure and functions
Cytology
“Father of Cytology”
Robert Hooke
It refers to all body cells
except sex cells. Ex. Nerve
cell, muscle cell
* It contains a Diploid (2n)
number of chromosomes.
* It undergoes mitosis.
Somatic cell
The sperm cell of the male
and the egg cell of the female
* Contains haploid (n) number
of chromosomes
* Undergo meiosis
Sex cells (gametes)
It has nuclear material in the center
of the cell, but is not enclosed by a
nuclear membrane; no membranebound organelles; found in bacteria
and blue-green bacteria
Prokaryotic cell
It contains a clearly defined nucleus
enclosed by a nuclear membrane
and membrane-bound organelles;
found in plants, animals, fungi, and
protists.
Eukaryotic cell
Outer layer of plant cells; produced
by the cytoplasm; gives shape and
rigidity to the cell; cellulose the
basic constituent.
Cell wall
Green (contain chlorophy II) sites of
photosynthesis in thylakoid
membranes, amino acid and fatty
acid synthesis
Chloroplast
In non-dividing cells, threads of
deoxyribonucleic acid (DNA) plus
associated proteins (histones) that
are attached to sites on the nuclear
envelope; condenses into a compact
mass when cells divide, forming
chromosomes that carry the genes
Chromatin
Living cellular material exclusive of
the nucleus
Cytoplasm
Matrix of protein fibers that gives
support and on which organelles,
enzymes, macromolecules are
attached; composed of two kinds of
protein filaments with similar
functions
Cytoskeleton
Liquid portion of the cytoplasm in
which cellular structures are
suspended; also called the
cytoplasmic matrix.
Cytosol
An extensive membranous system of
flattened sacs (cisternae) (ER) that
extends throughout the cytoplasm
as a communication and transport
system
Endoplasmic reticulum
is covered with
ribosomes and delivers proteins:
smooth; Cisternal
Rough ER
lacks ribosomes,
synthesizes lipids; tubular
Smooth ER
extensions of cytoplasm enclosed by
the plasma membrane that project
from the cell wall; made of two
microtubules surrounded by nine
others (9+2 structure)
Flagella and Cillia
Collection of Golgi bodies
(dictyosomes) that are stacks of
flattened cisternae associated with
secretion: some synthesize and
export polysaccharides; others
handle glycoproteins
Golgi complex
sites of
aerobic respiration and release of
adenosine triphosphate (ATP);
similar to like plastids in being
semiautonomous and containing
DNA and ribosomes; also reproduce
by fission; inner membrane with
many folds or cristae
Mitochondria
Pair of fused membranes around
the nucleus; connected to the
endoplasmic reticulum; contains
pores through which the
nucleoplasm and cytoplasm
connect
Nuclear envelope
Structure that contains the genetic
information (DNA) in eukaryotic
cells; controls cellular activities.
Nucleus
Outer boundary of the cytoplasm; a
lipid bilayer with embedded
proteins; differentially permeable
and regulates movement of
materials into and out of cells;
coordinates synthesis of cell wall;
recognizes and transmits internal
and external chemical signals
Plasma membrane
Strands of cytoplasm that connect
adjacent cells are pathways for
material movement.
Plasmodesmata
