Cell biology Protein structure Complex carbohydrates Complex carbohydrates

Cell biology

Protein structure

Complex carbohydrates

Announcements * There will be a quiz next laboratory session and like always; it will cover materials from previous lab. and from up-coming one. * Next week lab. is Energy conversion (fermentation). * Home work for this lab. will is posted on my web page. *Another assignment; a prospectus, also due next week and is posted on my web page. * Read through page XIV and XV to be prepared for next week assignment.

Today -cells and types of cells -Domains of life -Prokaryotes and eukaryotes -Cell division -Diffusion -Osmosis

The Cell * It is the smallest unit of any living organism. * It is basically a protoplasmic mass; that is a cell membrane and cytoplasm. * The cytoplasm is composed of a fluid part (cytosol) and solid structures (organelles) * Some other structures may exist depending on the type of the cell (cell wall in plant cells, cell wall in bacteria). * Based on the type of cell, living organisms are group into three categories.

Domains of life

Cell type * Generally, cells are either prokaryote or eukaryote * Prokaryotes -genetic material (chromosomal DNA) is free in the cytosol. - there is no membrane-bound organelles -no cytoskeleton * Eukaryotes -genetic material (chromosomal DNA) is surrounded by a membrane (the nuclear membrane) -there are membrane-bound organelles (endoplasmic reticulum, Golgi apparatus, mitochondria, chloroplast, etc. ) -there is cytoskeleton

Prokaryotes * These are bacteria (eubacteria) * unicellular * They have different shapes, size and environment. * Some are pathogenic and others are beneficial. * Microscopic organisms.

Archaea * These are middle stage between prokaryotes and eukaryotes. * They have ribosomal subunits that is different from bacteria and eukaryotes. * They live in extreme environmental conditions. * They share bacteria in -no membrane-bound organelles -no cytoskeleton -method of cell division - unicellularity * They resemble eukaryotes in - transcription apparatus

Eukaryotes * These includes cells of animals, plants, protozoa, and fungi. * Eukaryotic organisms either uni- or multi-cellular * Humans are multi- cellular eukaryotes. animal cell

Eukaryotes Plant cell

Cell division * Porkaryotes and Archaea - Cell division occur by process termed “simple binary fission” - Basically, the cell double its contents and divide - It a processes of reproduction (multiplication). * Eukaryotes -mitosis… somatic or asexual cell division -meiosis… sexual cell division - in multi-cellular organism e. g human, mitosis is mainly growth related cell division.

Diffusion * It is the process by which particles are transported across the cell membrane. * Particles moves from a region of higher concentration toward a region of lower concentration. * Cell membrane exert a degree of selectivity on the particle that diffuse through it (selective permeability) * O 2, Co 2, nutrients, etc. diffuse through the cell mem.

Osmosis * It is a process of water molecules movement from hypotonic solution (low solute concentration) to hypertonic solution (high solutes concentration) through a semi-permeable membrane (cell membrane). * Cytoplasm is a hypertonic solution compared to tap water. * What will happen to animal cell thrown into a beaker filled with tap water. . plant cell … Bacterial … * Saline …. 0. 9% Na. Cl, is isotonic solution.

Fun time *15 minutes to read the materials and methods for this laboratory. P 3 -4 to 3 -9 * Check each station and start work.