Transcript الشريحة 1
Cell Structure Object: to study the general structure of the cell, morphological variation (shapes) and size of cells through the light microscope. History In the 1600s, Anton Van Leevwenhoek used a single lens microscope to view bacteria Leevwenhoek’s microscope 2- Robert Hook (1635 – 1703): discovered small “rooms” called CELLS under a piece of cork Robert Hook’s Microscope: 3 – Scientists (Schwann, Schleiden and Virchow) put the CELL THEORY in (1882) a – Cells are basic unit of living things b – All living things are made up of cells c – New cells come from pre-existing cells Classification of Cells Eukaryotes Prokaryotes e.g., Bacteria Free Cells Cells as a unit Amoeba Reproductive cells Somatic cells Euglena Paramecium Trypanosoma eggs sperms Types of Cells: Prokaryotes Ex. Bacteria and Blue green Algae Eukaryotes Ex. Plants, Animals, Fungi, and Protists But, what are the characteristics of prokaryotes and eukaryotes? Differences between prokaryotic & eukaryotic cells PROKARYOTIC EUKARYOTIC No nucleus [nucleoid instead] DNA circular and not complexed with protein Nucleus with envelope Smaller than eukaryotes DNA linear and with protein to form chromatin larger than prokaryotes No membrane bound organelles Many membrane bound organelles Simple cells highly specialized. Typical prokaryotic structures Typical shapes of bacteria Characteristic grouping (or not grouping) Cocci do not have flagella Cell Shapes Cell Sizes frog or fish egg are the largest individual cells easily visible, approx. 1mm diameter human or sea urchin egg, approx. 100 m diameter typical somatic cell, approx. 20 - 70m plant cells are larger, approx. 10 -100 m bacteria are smaller, approx. 1- 5 m Cell Size Levels of Organization Cell tissue organ organ system Different types of cells: Protists: single eukaryotic cells: such as: 1- Amoeba 2- Paramecium 3- Euglena 4- Trypanosomes 1- Amoeba proteus 2 – Paramecium caudatum 3 – Euglena Viridis 4 – Trypanosoma spp. Representative Animal Cell Representative Plant Cell Components of Blood Blood is a mixture of cellular components suspended in plasma: 1. Erythrocytes (RBCs) 2. Leukocytes (WBCs) 3. Thrombocytes (platelets) Total Blood Volume: 8 % of body weight 2.75 / 5.5 liters of blood is plasma (remaining is the cellular portion) Centrifuged Blood Sample Separation of Components Plasma = Less Dense Platelets / WBC’s RBC’s More Dense RBC’s WBC’ s Microscopic Views Fish Blood Bird Blood Horse Blood Frog Blood Cat Blood Dog Blood Human Blood Snake Blood