Download Biological Sciences

Course Objective
 Understanding of biology based personal or social problems and
issues such as health, nutrition, environmental management
and human adaptation.
 Ability to resolve problems and issues in a biosocial context
involving values or ethical consideration
 Understanding of basic biological principles such as genetics,
nutrition, evolution, reproduction of various life forms,
structure & function, relationship, diseases, diversities,
integration of life systems, life-cycle, & energetic.
Benefits of Biological Sciences
 Focusing on Agriculture & Industry
 Environmental issues
 Biological warfare
 Aid to scientific communities
Learning outcome
 Learning the potential of Engineering Living System
 Understand key common features of Living System,
Cellular structure & function
 Basic understanding of cellular metabolism,
Physiological processes & Metabolic engineering
 Basic of Cell Division, Gene Control & Expression
 Basic understanding of practical aspects of genetic
engineering
Benefits of Biotechnology
 Genetically engineered food
 High yield varieties
 Pest & disease control
 Less erosion
 Human applications
 Transgenic animals/ plants
 Health care & diagnosis …
Significance & Applications
 Synthetic Biology
 Inclusion of technology in daily life
 Chemical Engineering - Eg. Bio-fuels, bio warfare
 Civil Engineering – Eg. Waste Management, Forestation
& Deforestation
 Agriculture Engineering - Eg. Agricultural tools and
techniques, High yield products, Composting etc
Biology - Definition
Biology is the science of life forms and
living processes.
Salient Features of Living Beings
– Animals as well as Plants
 Growth
 Reproduction
 Metabolism
 Cellular Composition
 Sensibility
Branches of Biology
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Taxonomy
Anatomy
Cytogenetics (Cytology + Genomics)
Histology
Physiology
Neurology
Endocrinology
Ecology
Applied Biology/ Synthetic Biology:
 Anthropology
 Sericulture
 Apiculture
Ichthyology
Pisci-culture
Dairy
and alike…
Cytology
Cytology is study of structure and function of cell
Cell is structural and functional unit of life.
Life forms: Unicellular & Multicellular organisms
Unicellular Organisms are capable of :
i. Independent existence
ii. performing the essential functions of life.
Discovery of Cell
Robert Hooke (mid-1600s):
 Observed sliver of cork
 Saw “row of empty boxes”
 Coined the term “cell”
Cell Theory
Propounded by Matthias Schleiden (a botanist, 1838)&
Theodor Schwann (a zoologist, 1839):
 All the living organisms are composed of cells and product of
cells
 Smallest living unit of structure and function of all
organisms is the cell
 All cells arise from the pre-existing cells
Cell Structure
Cell Size
Cell Size
1. 1–100µm
2. Why is there a limit to cell size?
a. Surface-to-volume ratio
b. Distance from surface to center
tallest trees
adult human
chicken egg
frog embryo
most eukaryotic cells
mitochondrion
most bacteria
virus
proteins
diameter of DNA
double helix
atoms
Surface-Area Ratio
Characteristics of All Cells
 A surrounding membrane
 Protoplasm – cell contents in thick fluid
 Organelles – structures for cell function
 Control center with DNA
Cell Types
 Prokaryotic
 Eukaryotic
Prokaryotic Cells
 First cell type on earth
 Cell type of Bacteria and Archaea
Prokaryotic Cells
 Have no membrane-bound
organelles
 Include true bacteria
 On earth 3.8 million years
 Found nearly everywhere
 Spores in each breath; intestines
 Naturally in soil, air, hot springs
Eukaryotic Cells
 Nucleus bound by membrane
 Include algae, fungi, plant and animal cells
 Possess many organelles
Protozoan
Representative Animal Cell
Representative Plant Cell
microtubules
(part of cytoskeleton)
mitochondrion
chloroplast
Golgi complex
central vacuole
smooth endoplasmic
reticulum
vesicle
cell wall
rough endoplasmic
reticulum
plasma
membrane
nucleus
nucleolus
nuclear pore
chromatin
nuclear envelope
intermediate
filaments
ribosomes
free ribosome
nucleoid (DNA)
ribosomes
food granule
prokaryotic
flagellum
plasma membrane
cytoplasm
cell wall
Cell Organelles
 Cellular machinery
 Two general kinds
 Derived from membranes
 Bacteria-like organelles
Cell Walls
 Surrounds plasma membrane
 Found in fungi & plant cells
 Chemical Composition of cell wall:
 Fungi – Chitin; Plant Cells - Cellulose
Plasma Membrane
 Contains cell contents
 Double layer of phospholipids & proteins
Movement Across the Plasma Membrane
 Hence known as Selectively Permeable Membrane
 A few molecules move freely such as Water, Carbon dioxide,
Ammonia, Oxygen
 Carrier proteins transport some molecules
 Proteins embedded in lipid bi-layer
 Fluid mosaic model – describes fluid nature of a lipid bilayer with proteins
Phospholipids
2 Parts of Phospholipids:
 Hydrophilic head
 Hydrophobic tail
Membrane Proteins
1. Channels or transporters
 Move molecules in one direction
2. Receptors
 Recognize certain chemicals
Membrane Proteins
3. Glycoproteins
 Identify cell type
4. Enzymes
 Catalyze production of substances
Cytoplasm
 Viscous fluid containing organelles
 components of cytoplasm:
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Interconnected filaments & fibers
Fluid = cytosol
Organelles (not nucleus)
storage substances
Cytoskeleton
Filaments & fibers
Composed of 3 types:
 Microfilaments
 Microtubules
 Intermediate filaments
Performs 3 functions:
 mechanical support
 anchor organelles
 help move substances
Nucleus
 Control center of cell
 Double membrane
structure
 Contains :
 Chromosomes
 Nucleolus
Nuclear Envelope
 Separates nucleus
from rest of the cell
 Double membrane
porous structure
nuclear
envelope
nucleolus
nuclear
pores
chromatin
nucleus
nuclear
pores
Function of Nucleolus
 Directs synthesis of RNA
 Synthesis of ribosome
DNA
 Hereditary material
 Composition of DNA:
 N- Base Pairs
 Pentose Sugar
 Phosphate
 Functions of DNA:
 DNA Replication
 Proteins Synthesis
 Form the basis for cell division
Membranous Organelles
 Functional components within cytoplasm
 Bound by membranes
Let’s revise……
 Define Biology.
 Name two types of cells.
 Give one similarity between Prokaryotes and Eukaryotes.
 _________is present in plant cell only.
 Mitochondria is also known as ____________
 Suicidal bags are _____________.
 Cell organelles are bounded by_______and ________in
the cytoplasm.
Eukaryotic cell structure
 Nucleus is control center of the cell
 1. Membrane bound (nuclear envelope)
 2. Contains nucleoli; synthesizes ribosomal RNA
 3. DNA in chromosomes (DNA and proteins)
Eukaryotic cell structure
Organelles
Endoplasmic reticulum consists of folded membranes
attached to the nucleus
Rough ER is site for protein synthesis
Smooth ER is site for Lipid synthesis
Eukaryotic Cell Structure
Organelles (cont.)
Ribosomes assemble amino acid into polypeptide
chains
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a. Associated with the ER
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b. Composed of RNA and proteins
Eukaryotic Cell Structure
 Organelles (cont.)
 Golgi apparatus are membranous sacs
associated with ER
•
a. Processing and transport of proteins, lipids
•
b. Synthesis and transport of polysaccharides
Eukaryotic cell structure
 Organelles (cont.)
 Lysosomes are Golgi-derived vesicles containing
digestive enzymes
Eukaryotic Cells: Organelles
Energy sources for cell activities
 Mitochondria provide energy for cellular
functions (respiration)
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a. Membrane bound, numerous
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b. Matrix/cristae
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c. Have their own DNA and ribosomes;
self-replicate
Eukaryotic Cells: Organelles
Energy sources for cell activities
• Chloroplasts—function in photosynthesis
 1) Green—contain chlorophyll pigment
 2) Stroma/grana (thylakoid stacks)
 3) Have their own DNA and ribosomes; self-replicate
 4) Up to 100 per cell
Eukaryotic Cells: Organelles
 Cytoskeleton
 Internal infrastructure
 Surface structures
 extensions of the plasma membrane
 aid in movement of simple organisms
Mitochondria
 Have their own DNA
 Bound by double
membrane
Mitochondria
 Break down fuel molecules (cellular respiration)
 Glucose
 Fatty acids
 Release energy
 ATP
Chloroplasts
 Derived form photosynthetic bacteria
 Solar energy capturing organelle
Photosynthesis
 Takes place in the chloroplast
 Makes cellular food – glucose
Endoplasmic Reticulum
Types of Endoplasmic Reticulum:
 Rough Endoplasmic Reticulum
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Supplemented with ribosome
 Smooth Endoplasmic Reticulum
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Devoid of ribosome
Function of Endoplasmic Reticulum:
 Helps in movement of substances within the cell
 Network of interconnected membranes
 Provides skeleton/ skeleton to the cell
Rough Endoplasmic Reticulum
 Ribosome attached to surface
 Manufacture protein
 Not all ribosome attached to rough ER
 May synthesize proteins from ribosome
Smooth Endoplasmic Reticulum
 No attached ribosome
 Hollow Tubular structure
 Has enzymes that help in synthesizing:
 Carbohydrates and
 Lipids
Golgi Apparatus
 Involved in synthesis of plant cell wall
 Packaging & shipping station of cell
Golgi Apparatus Function
1. Molecules come in vesicles
2. Vesicles fuse with Golgi membrane
3. Molecules may be modified by Golgi
Golgi Apparatus Function (Continued)
4. Molecules pinched-off in separate vesicle
5. Vesicle leaves Golgi apparatus
6. Vesicles may combine with plasma membrane to secrete
contents
Vacuoles
 Membrane bound storage sacs
 More common in plants than animals
 Contents
 Water
 Food
 wastes
Cilia & Flagella
Cilia
 Short
 Used to move substances
outside human cells
Flagella
 Whip-like extensions
 Found on sperm cells
Function:
 Provide motility
Structure of Cilia & Flagella
 Bundles of microtubules
 Associated with plasma membrane
Centrioles
 Pairs of micro-tubular structures
 Play a role in cell division
Lysosomes
 Contain digestive enzymes
 Functions
 Aid in cell renewal
 Break down old cell parts
 Digests invaders
Prokaryotes & Eukaryotes
 Similarities & differences
 Both surrounded by plasma membrane, but very
different
 Prokaryotes – Archaebacteria and Eubacteria
 Eukaryotes – everything else
Evolution of Eukaryotic cell
Endosymbiotic Hypothesis
Similarities between bacteria, mitochondria and chloroplasts
Self-reproducing by binary fission
Size of organism and genome
Single circular naked DNA
Proportion of (G & C) to (A & T)
Same sized ribosome
Protein synthesis inhibited by antibiotics
Enzymes for synthesis of DNA, RNA and protein
Electron transport system
Plant & Animal Cells
 Similarities
 Both constructed from eukaryotic cells
 Both contain similar organelles
 Both surrounded by cell membrane
Plant & Animal Cells
 Differences
 Plants have
 Cell wall – provides strength & rigidity
 Have chloroplasts, photosynthetic
 Animals have
 Other organelle not found in plants (lysosomes
formed from Golgi)
 Centrioles, important in cell division