CELL 1 Flashcards
The ______ is coined as the basic living unit of all organisms.
cell
Concluded that all plant and animal tissues were composed of cells.
Matthias Schleiden and Theodor Schwann
cells are composed primarily of four significant elements-
carbon
oxygen
hydrogen
nitrogen.
was the first person to use the term “cell”. He referred to the small empty chambers in the structure of cork as cells.
Robert Hooke
proposed the theory of biogenesis where cells only arise from pre-existing
cells.
Rudolf Virchow
A ______ is the basic structural and functional unit of living organisms.
cell
Types of Cell
Eukaryotic cell
Prokaryotic cell
composed of organelles that are membrane bound structures, each having a unique role and containing a specific complement of proteins and other molecules.
Eukaryotic cell
ack of membranous subcellular organelles which are possessed by the eukaryotes, but they are still able to perform the necessary processes of life.
Prokaryotic cell
- DNA is found in the nucleus of the cell.
- Contain membrane-bound organelles which include mitochondria, endoplasmic reticulum, and Golgi complex
- Cell division involve mitosis.
EUKARYOTES
- DNA is not enclosed within the membrane.
- Lack membrane-enclosed organelles
- Usually divide by binary fission.
PROKARYOTES
contain subcellular structures and well-defined nucleus.
Eukaryotes
Structure: Phospholipid bilayer containing cholesterol and proteins and some carbohydrates; forms a selectively permeable boundary of the cell.
Plasma Membrane
Functions: Acts as a physical barrier to enclose cell contents; regulates material movement into and out of the cell; functions in cell communication
Plasma Membrane
o Structure: It is enclosed within a double membrane called nuclear envelope; contains nucleolus
Nucleus
o Function: It contains the DNA that serves as the genetic material for directing protein
synthesis.
Nucleus
: It consists of RNA and proteins which functions in ribosomal unit assembly.
Nucleolus
: It surrounds the chromatin and the nucleoli.
Nucleoplasm
`o Structure: This can be seen between the plasma membrane and the nucleus where
the other cellular elements are embedded.
Cytoplasm
o Function: It is responsible for various cellular processes.
Cytoplasm
are membrane-bound structures which carry out specific metabolic
activities of the cell.
Organelles
provides support for organelles and serves as the viscous fluid medium.
Cytosol
o It is further subdivided into:
▪ Rough endoplasmic reticulum
▪ Smooth endoplasmic reticulum
Endoplasmic Reticulum
Structure: Extensive interconnected membrane network that varies in shape; ribosomes attached on the cytoplasmic surfaces
Rough endoplasmic reticulum
- Functions: Modifies, transports, and stores proteins produces by
attached ribosomes
Rough endoplasmic reticulum
are involved in the protein synthesis.
Ribosomes
- Structure: Extensive interconnected membrane network lacking ribosomes
Smooth endoplasmic reticulum
- Function: Synthesizes, transports, and stores lipids; detoxifies drugs;
forms vesicles and peroxisomes
Smooth endoplasmic reticulum
o Structure: Series of several elongated, flattened saclike membranous structures.
Golgi Apparatus
o Functions: Modifies, packages, and sorts materials, that arrive from the endoplasmic reticulum in transport vesicles
Golgi Apparatus
▪ ___________ transport cellular material. Mature vesicles are called secretory vesicles.
Vesicles
o Structure: Double-membrane-bound organelles containing a circular strand of DNA
Mitochondria
o Function: It is responsible for the production of energy in the form of ATP.
Mitochondria
▪ is highly permeable to small molecules, due to the presence of a pore-forming protein called porin.
Outer membrane
▪ contains many proteins that participate in oxidative phosphorylation.
Intermembrane
▪ has multiple folds projecting inwards, called cristae.
Inner membrane
o Structure: Spherical shaped membrane bound organelles formed from the golgi apparatus; contain digestive enzymes
Lysosomes
o Function: Digest microbes or materials by the cell
Lysosomes
o Structure: Small vesicles surrounded by a membrane
Peroxisomes
o Structure: Organized network of protein filaments
Cytoskeleton
o Function: Involved in the biosynthesis of cholesterol (peroxidase enzymes)
Peroxisomes
o Function: Maintains integral structural support and organization of cells
Cytoskeleton
▪ maintain cell shape.
Microfilaments
▪ provides structural support.
Microtubules
▪ give mechanical support to structures like nucleus and plasma membrane.
Intermediate filaments
- Diffusion is the movement of a substance from an area of its higher concentration to an area of its lower concentration.
Passive Transport Process
o is the type of diffusion of
dissolved solutes through the plasma membrane
Simple diffusion
o is the type of diffusion that requires a protein carrier.
Facilitated Diffusion
o is the diffusion of water point across a selectively permeable membrane
Osmosis
- This type of cell membrane transport uses energy (ATP) provided by the cell.
Active Transport Process
- refers to bulk movement of substance into the cells by vesicles forming at the plasma membrane.
Endocytosis
- refers to bulk movement of substance out of the cell by fusion of secretory vesicles with the plasma membrane.
Exocytosis
o The DNA molecule is duplicated exactly in a process called ________________ which occurs toward the end of the interphase.
DNA replication
o It is the longer phase of the cell cycle where the cell is active and preparing for cell division.
Interphase
onsists of four stages-prophase, metaphase, anaphase, and telophase. The result is two daughter nuclei, each identical to the mother nucleus.
Mitosis
▪ - each chromosome consists of two chromatids joined at the centromere.
Prophase
▪ - chromosomes align at the center of the cell
Metaphase
▪ - two new nuclei assume their normal structure, and cell division is completed, producing two new daughter cells.
Telophase
▪ - chromatids separate at the centromere and migrate to opposite poles.
Anaphase
