INTRODUCTION TO MEDICAL BIOLOGY

A.B. Yulianti, Dra, MSiBiologi Medik FK UNISBA

INTRODUCTION TO MEDICAL BIOLOGY- BIOLOGY: THE SCIENCE THAT DEALS WITH

PHENOMENA OF LIFE AND LIVING ORGANISMS IN GENERAL

- MEDICAL BIOLOGY: THE BIOLOGY PERTAINING TO THE MEDICAL SCIENCES

BIOLOGY CONCERNED WITH MEDICAL SCIENCE

BIOLOGY OF THE CELL

HUMAN GENETICSHUMAN EMBRYOLOGY

LIVING THINGS ARE ORGANIZEDCells tissues organs systems organism (multicellular individual)

All organisms of one type belong to a population

The population of various organisms make up a community

THE CELL The cell is the basic unit of life. All organisms are made up of cells (or in

some cases, a single cell). Most cells are very small; most are invisible

without using a microscope. Cells are covered by a cell membrane and

come in many different shapes. The contents of a cell are called the

protoplasm.

TYPE OF CELL Prokaryote

Eukaryote

Plant

Animal

Phylogenetic Tree of Life

Prokaryotic cells consist of a single closed compartment that is surrounded by the plasma membrane

Lacks a defined nucleus, and has a relatively simple internal organization.

All prokaryotes have cells of this type. Bacteria, the most numerous prokaryotes, are single-celled organisms.

Prokaryote

EUKARYOTE

Eukaryotic cells contain extensive internal membranes that enclose specific regions, separating them from the rest of the cytoplasm, the region of the cell lying outside of the nucleus.

These membrane define a collection of subcellular structure called organelles

Eukaryotes include all members of protist, fungus, animal and plant kingdoms,from the most primitive ferns to the most complex flowerng plants,and from amebas and simple sponges to insects and mammals.

THE DIFFERENCE BETWEEN PROKARYOTIC AND EUKARYOTIC

Lacks a defined nucleus

Relatively simple internal organization.

Lacks of organelle only ribosome and simple cytoskeleton

Circular DNA/Nucleoid Amitosis Single –cell coloni

Defined nucleus Complex internal

organization extensive membrane compartments organelles.

Double helix Mitosis and Meiosis Multiple-cell tissue

Prokaryote Eukaryote

SIMILARITY BETWEEN PROKARYOTE AND EUKARYOTE Surrounded plasma membrane Chemical composition

Water Protein Lipid Mineral

A typical human or animal cell with the organelle

Eukaryote

COMPONENT OF EUKARYOTE Plasma membrane Protoplasm

Cytoplasm cytosol Organelles

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The organelles are:

- Nucleus- Nucleolus- Ribosome- Endoplasmic reticulum

- Golgi Apparatus-Vacuole and vesicle-Lysosome- Mitochondria- Cytoskeleton- Peroxisome or microbodies- Cilia and Flagella

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• THE CYTOSOL IS THE FLUID REGION OF THE CELL CYTOPLASM THAT LIES OUTSIDE OF THE ORGANELLES.

THE CYTOSOL OF MANY CELLS CONTAINS INCLUSION BODIES, GRANULES THAT ARE NOT BOUNDED BY A MEMBRANE.

.

The Cytosol

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SOME CELLS-SPECIFICALLY, MUSCLE CELLS AND HEPATOCYTES-CONTAIN CYTOSOLIC GRANULES OF GLYCOGEN.

THE CYTOSOL OF THE SPECIALIZED FAT CELLS IN ADIPOSE TISSUE CONTAINS LARGE DROPLETS OF ALMOST PURE TRIACYLGLYCEROLS, A STORAGE FORM OF FATTY ACIDS.

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IN ADDITION, THE CYTOSOL IS A MAJOR SITE OF CELLULAR METABOLISM AND CONTAINS A LARGE NUMBER OF DIFFERENT ENZYMES.

ITS PROTEIN COMPOSITION IS HIGH (ABOUT 20-30 PERCENT OF THE CYTOSOL IS PROTEIN, AND THE CYTOSOL CONTAINS 25-50 PERCENT OF THE TOTAL PROTEIN WITHIN CELLS).

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An animal cell, the organelles are small, membranous cellular inclusion, floated in the cytosol.

They keep various cellular activities separated from one to another.

Organelles

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Nucleus

Nucleus is a largest organelle, has a dia meter of about 5 μm.

Prominent organelle in eukaryotic cell

Stores genetic information

Separated from the cytoplasm by nuclear envelope.

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Nuclear envelope or nuclear membrane consists of inner membrane and outer membrane.

The space between inner and outer membrane is continues with the lumen of rough endoplasmic reticulum.

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The two nuclear membranes fuse at the nuclear pores.

Nuclear pores are constructive of specific set of membrane protein.

It functions as channel between the nucleus and the cytosol.

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It regulates the movement of the material from and to the nucleus.

Protein fibers associated with the inner membrane of the nuclear envelope

Protein fibers maintain the shape of nucleus and provide chromatin attachment.

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The nucleus contains the nucleoplasm, the nucleolus, fibrous matrix, DNA-protein complex, chromatine-chromosome.

Chromatine looks grainy, but actually it is thread like material.

Chemical analysis shows that chromatine and chromosomes contain DNA, protein and some RNA

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Chromatin undergoes coiling into chromosome just before the cell divides

It is immersed in the nucleoplasm

Nucleoplasm is sugested has a different composition from cytosol

The DNA of all chromosomes is packaged into a compact structure with the aid of specialized proteins.

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It is traditional to divide the DNA-binding proteins in eucaryotes into two general classes: the histones and the nonhistone chromosomal proteins.

The complex of both classes of proteins with the nuclear DNA of eucaryotic cells is known as chromatin.

Histones are unique to eucaryotes.

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DNADNA is the hereditary or genetic material.

DNA stores information regarding its own replication and the order in which amino acid are to the joined to make protein

Nucleotide is a molecular complex of three types of molecule: phosphate, pentose sugar and a nitrogen containing base.

DNA is double stranded, the two strands twisted about each other in the form of double helix.

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The sugar in DNA is deoxyribose → deoxy ribonucleic acid.

The bases in DNA consist of purine (two rings) and pyrimidine (one ring).

The purine: Adenine (A) and Guanine (G)

The pyrimidine:Thymine (T) and Cytosin (C)

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The sugar and phosphate as the backbone of the strand and the bases project to one side of the backbone.

Between the strands, Thymine (T) always paired with Adenine (A) and Guanine (G), with Cytosin (C).

It is called complementary.

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NUCLEOLUS

Usually one nucleus has one nucleolus, but sometime one nucleus has more than one nucleolus or nucleoli.

Nucleolus is the one or two dark regions of the chromatine, where ribosomal RNA (rRNA) is produced.

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rRNA joints with protein to form subunits of the ribosomes.

The subunits of the ribosome leave the nucleus enter the cytoplasm.

The subunits joint together in the protein synthesis.