Cell and Molecular biology Flashcards
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
Semiautonomous, contain DNA and
ribosomes and reproduce by fission;
have an elaborate internal
structure; in algae and plants
Plastids
First wall deposited by actively
growing and dividing cells
Primary wall
Sites of protein assembly in the
cytoplasm or on the rough ER: are
small (17-23 m) particles assembled
from a large and a small subunit
produced in the nucleolus
Robosome
at sites of active
synthesis clusters of ribosome
Polysome
Deposited inside primary wall after
cell has stopped growing;
Secondary wall
Sac of liquid, the cell sap,
surrounded by a membrane, the
tonoplast
Vacuoles
Small sacs of secretory material
pinched off from the cisternae
Vesicles
move
from the Golgi complex to the
plasma membrane (with the
assistance of actin filaments) and
liberate their contents outside of the
cell
Exocytosis
is the longest part of the cell cycle. Interphase has
stages:
G1 phase, S phase, and G2 phase.
Interphase
cells become bigger in size, duplicates organelles.
G1 phase
DNA synthesis
S phase
resting phase of the cell; neither dividing nor preparing
G0
reorganizes cell’s organelles and condensation of DNA
G 2 phase
It is the process of copying and dividing the entire cell
Cell division
binary fission (bacteria and fungi), mitosis, and
meiosis
3 types od cell division
division of nucleus of the cell. It is known as equational division
Mitosis
Duplicated chromosomes and spindle fibers appear.
Prophase
Duplicated chromosomes line up randomly in the
center of the cell between spindle fibers.
Metaphase
Duplicated chromosomes pulled to the opposite pole
end of the dividing cell.
Anaphase
Nuclear membrane forms around chromosomes at each
end of the cell, spindle fibers disappear; chromosomes disperse
Telophase
division of plasma membrane; two daughter cells result
with exact genetic information
Cytokinesis
Two daughter cells (somatic)
* Same number of chromosomes as original cell (humans have 46)
Results of mitosis
produces cells containing half number of double
stranded chromosomes
First meiosis division
results in formation of four cells. Each cell with
half the number of single stranded chromosomes (haploid).
Second meiosis division
it is the process of creating sperm cell
Spermatogenesis
- Each primary egg cell develops into one large haploid cell and
three smaller haploid cells called polar bodies
Oogenesis
states that DNA contains instructions
for making a protein, which are copied by RNA. Apparently, DNA to
RNA to Protein.
Central dogma of molecular biology
. Phosphate group
2. Sugar
3. Nitrogenous base
Parts of nucleotide
- It is messenger RNA, the main copy of DNA. DNA must be
copied to mRNA because DNA is a large molecule that cannot pass
through the pores of a nuclear envelope
mRNA
It is ribosomal RNA, the main constituent of ribosomes produced
in the nucleolus.
rRNA
-It is transfer RNA. It is a type of RNA that contains anticodon
which reads the codon from mRNA
tRNA
It is a three consecutive nitrogen base that can be found in
mRNA. Each codon has a corresponding amino acid. There are 20
naturally occurring amino acids.
Codon
A three-nucleotide sequence on tRNA that associates with the
equivalent mRNA sequence.
Anticodon
can form body structures, enzymes, for immunity and among
others
Proteins
- DNA is replicated or duplicated. DNA replication is said
to be semi-conservative.
Replication
DNA is transcribed to mRNA through different
enzymes. We use the DNA strand as a template in making a strand of
mRNA.
Transcription
from mRNA to protein
Translation
AUG (Methionine)
Start codon
UAG, UGA, UAA
Stop codon
