1 Zoology 106 course General Animal Biology For Premedical Student By Dr. Ashraf M. Ahmed H

2 Questions Considered Why do certain reactions occur? Why do others not occur? What drives these processes? Why do organic molecules have certain properties? Can we predict the presence or absence of certain properties? Can we make new materials with other desired properties?

3 Roles My role Professor Guide Your Role Student Understand the material!

4 Homework Every problem in the Text is assigned. However, They will not be graded. They will not be collected. They will not be discussed in class. They are available to you to determine if you understand the material.

5 Attendance Assumption: you are adult students Attendance in lecture is expected Attendance at tests is expected. A missed examination will receive a zero. No excuses will be accepted. A missed final exam will receive a zero.

6 A Word on the Final Exam

7 Communication in Class During my class you should Turn your cell phone off. Turn your desire to communicate with anyone but me off.

8 Expectations A professional student is expected to attend class purchase course materials study do the homework be prepared for class be prepared for tests do well

9 Doing Well Read the chapter before lecture Attend lecture Take notes Do not rely on copies of Power Points Re-read the chapter after lecture Review lecture notes daily Rewriting the lecture notes is strongly suggested Keep, maintain, and study note cards Do homework problems. Form a study group Learn the functional groups

Good Luck Dr. Ahmed Abdel.Zaher 10

11 The Cell The Organism’s Basic Unit of Structure and Function ProkaryoticProkaryotic EukaryoticEukaryotic Types of cells of cells Micro-organisms All other forms of life Cellulae (Small room) بدائية الكائنات الدقيقة متقدمة

12 Cell Theory 1- All organisms are composed of one or more of cells. 2- Cell is the basic unit of life. 3- The new cell arises only from pre- existing cell.

All cells are surrounded by a plasma membrane غشاء بلازمى. All cells are surrounded by a plasma membrane غشاء بلازمى. The semi-fluid substance المادة النصف سائلة within the cell is called “cytosol”, السيتوبلازم containing the cell organelles عِضيات الخلية. The semi-fluid substance المادة النصف سائلة within the cell is called “cytosol”, السيتوبلازم containing the cell organelles عِضيات الخلية. All cells contain chromosomes which have genes in the form of DNA. All cells contain chromosomes which have genes in the form of DNA. All cells have tiny organelles عضيات صغيرة called “Ribosomes” that make proteins. All cells have tiny organelles عضيات صغيرة called “Ribosomes” that make proteins. 1). Prokaryotic and eukaryotic cells differ in size and complexity Similarities Similarities أوجه التشابه Page 112

A major difference الفرق الأساسى between prokaryotic and eukaryotic cells is the location of chromosomes موضع الصبغيات. A major difference الفرق الأساسى between prokaryotic and eukaryotic cells is the location of chromosomes موضع الصبغيات. In an eukaryotic cell, chromosomes are contained in a true nucleus (النواة ). In an eukaryotic cell, chromosomes are contained in a true nucleus (النواة ). In a prokaryotic cell, the DNA is concentrated in the nucleoid (شـبه نواة) without a membrane ( بدون غـشاء) separating it from the rest of the cell. In a prokaryotic cell, the DNA is concentrated in the nucleoid (شـبه نواة) without a membrane ( بدون غـشاء) separating it from the rest of the cell. In prokaryotic cell, DNA is a single strand (أحادى الشريط) or double strand (ثنائى الشريط) DNA. But in eukaryotic cell, DNA is double strand. In prokaryotic cell, DNA is a single strand (أحادى الشريط) or double strand (ثنائى الشريط) DNA. But in eukaryotic cell, DNA is double strand. 1). Prokaryotic and eukaryotic cells differ in size and complexity Differences Differences أوجه الإختلاف Page 112

(A)- Prokaryotes الكائنات وحيدة الخلية ذات النواة البدائية الكائنات وحيدة الخلية ذات النواة البدائية Page 112, 526 Micro-organisms Micro-organisms الأحياء الدقيقة

Prokaryotes BacteriaBacteriaArchaeaArchaea - Exist in extreme environments البيئات القاسية (hot and salty) - Exist in most environments They are differing in some other structural, biochemical and physiological characteristics صفات Types of Prokaryotes Page 526

1- BacteriaProkaryotes

Fig. 7.4 The prokaryotic cell is much simpler in structure, lacking a nucleus and the other membrane-enclosed organelles of the eukaryotic cell. Page 112 غشاء بلازمى الجدار الخلوى شبه نواة الريبوزومات الكبسولة الأسواط

Prokaryotic Cell Capsule Cell Wall Plasma membrane Cytoplasm ( Cytosol ) Nucleoid Ribosomes

Many prokaryotes (bacteria) secrete a sticky protective layer called capsule outside the cell wall, which has the following functions وظائف : Many prokaryotes (bacteria) secrete a sticky protective layer called capsule outside the cell wall, which has the following functions وظائف : 1. Adhere bacteria cells to their substratum. 1. Adhere تثبيت bacteria cells to their substratum السطح. 2. Increase bacteria resistance to host defenses. 2. Increase bacteria resistance المقاومة to host defenses مناعة العائل. 3. Stickتلصق ) ) bacterial cells together when live as colonies. 4. Protect bacterial cell. 4. Protect تحمى bacterial cell. Fig A) the bacterial capsule

In all prokaryotes, the functions of the cell wall are as following: تحافط 1. maintains تحافط the shape of the cell, الحماية الطبيعية توفر 2. affords physical protection الحماية الطبيعية توفر ( إنفجار ) البيئة ذات الضغط الأسموزى المنخفض 3. prevents the cell from bursting ( إنفجار ) in a hypotonic environment البيئة ذات الضغط الأسموزى المنخفض. peptidoglycan Most bacterial cell walls contain peptidoglycan ( a polymer of modified sugars cross-linked by short polypeptides ). ( تـفـتـقـد ) The walls of Archaea lack ( تـفـتـقـد ) peptidoglycan. B) The bacterial cell wall

It is a tool for identifying تعريف specific bacteria, based on differences in their cell walls. A)- Gram-positive ( Gram +ve ) bacteria: A)- Gram-positive ( Gram +ve ) bacteria: violet- تـُصبغ بنفسجيا Their cell walls have large amounts كمية كبيرة of peptidoglycans that react with Gram’s stain (appear violet- stained تـُصبغ بنفسجيا ). Fig. 27.5a Page 529 The Gram’s stain: صبغة جرام

B)- Gram-negative B)- Gram-negative ( Gram -ve ) bacteria: تظهر الصبغة their cell walls have no or small amount of peptidoglycan. So, do not react or very weakly react with Gram’s stain (do not appear stained لا تظهر الصبغة ) Fig. 27.5b Page 529 The Gram’s stain: صبغة جرام

Gram Staining of Bacteria Gram +ve bacteria: have Large amount of peptidoglycan that stained violet ( non-pathogenic غير ممرضة ). Gram +ve bacteria: have Large amount of peptidoglycan that stained violet ( non-pathogenic غير ممرضة ). Gram –ve bacteria: Have small amount or no peptidoglycan (no staining) ( pathogenic ممرضة ). Gram –ve bacteria: Have small amount or no peptidoglycan (no staining) ( pathogenic ممرضة ). Gram-negative species are pathogenic ( ممرضة ) more threatening ( أكثر خطورة ) than gram-positive species. Gram-negative species are pathogenic ( ممرضة ) more threatening ( أكثر خطورة ) than gram-positive species. Gram-negative bacteria are commonly more resistant ( أكثر ممانعة ) than gram-positive species to antibiotics للمضادات الحياتية. Gram-negative bacteria are commonly more resistant ( أكثر ممانعة ) than gram-positive species to antibiotics للمضادات الحياتية.

Prokaryotes reproduce ( تـتـكاثر ) only asexually ( لا جنسيا ) by binary fission ( الإنقسـام الثـنائى البسيط ). A single cell produce a colony of offspring. Fig Page 531 Mov Reproduction of Bacteria التكاثر فى البكتريا

Nutrition of Prokaryotes Nutrition of Prokaryotes التغذية فى الأحياء الدقيقة Prokaryotes are grouped into four categories according to how they obtain energy and carbonProkaryotes are grouped (صُنٍفـَت) into four categories (أنواع) according to how they obtain energy and carbon Nutrition refers to how an organism obtains energy and a carbon source from the environment to build the organic molecules of its cells.

Phototrophs ضوئية التغذية Phototrophs ( ضوئية التغذية ): Organisms that obtain energy from light. Chemotrophs كيميائية التغذية Chemotrophs ( كيميائية التغذية ): Organisms that obtain energy from chemicals in their environment. Autotrophs ذاتية التغذية Autotrophs ( ذاتية التغذية ): Organisms that use CO 2 as a carbon source. Heterotrophs متعدد التغذية Heterotrophs ( متعدد التغذية ): Organisms that use organic nutrients as a carbon source. Nutrition of Prokaryotes Nutrition of Prokaryotes التغذية فى الأحياء الدقيقة

 Photoautotrophs light energyCO 2  Photoautotrophs (ذاتية التغذية الضوئية): use light energy as energy source, and CO 2 as carbon source to synthesis (تخلق) organic compounds.  Chemoautotrophs inorganic substancesCO 2  Chemoautotrophs ذاتية التغذية الكيميائية)): use chemical inorganic substances as energy source, and CO 2 as a carbon source.  Photoheterotrophs use lightorganic substances  Photoheterotrophs (متعدد التغذية الضوئية): use light as energy source, and organic substances as carbon source.  Chemoheterotrophs  Chemoheterotrophs (متعدد التغذية الكيميائية): organic substances use organic substances as a source for both energy and carbon. There are four major modes of nutrition

Prokaryotic modes of nutrition Page 532 Based on Carbon source and Energy source that can be used by a prokaryote organism to synthesise organic compounds. AutotrophsHeterotrophs Photo- autotroph Chemo- autotroph Chemo- Heterotroph Photo- Heterotroph CO 2 as Carbon Source Organic compounds as Carbon ( C) Source - Light as energy source -CO 2 as C source - Chemicals as energy source -CO 2 as C source - Light as energy source -Organic compounds as C source - Chemicals as energy source - Organic compounds as C source Prokaryotes