BTY100-Lec#3.1 Cell Created By: Dr. Loveleen Kaur

Outline Cell Types of Cell Cell as factories Prokaryotic Eukaryotic Introduction to cell structure

Few Facts?

Understanding body makeup…

Are you aware that you started your life as a single cell??? It is interesting to understand how all small machines work together to create an organism.

CELL

Lets start with Cell We need to first understand how a cell function in order to understand how tissues work, and then how organs function, and then how our body works. It's kind of like.........you can't just start reading a book without first learning how words are put together.

Robert Hooke- Discovered cell Leeuwenhoek- Observed cell Cell is the structural and functional unit of life. Smallest part of the organism that retains characteristics of the entire organism. The place where the metabolic processes occur that keep the organism alive. Cells are sacs of fluid surrounded by membranees. Inside the fluid chemicals and organelles float. Surface area to volume ratio is crucial: leads to cell division Mathematical explanation of how surface area changes with change in volume

Discovery of Cells Robert Hooke (mid-1600s) Observed bark of oak tree Saw “row of empty boxes” Coined the term cell. Cell refers to the basic structural unit that makes up the all the living things.

Anton van Leeuwenhoek : make use of microscope to examine biological specimens. He gave name “animalcules” to the little animals he saw moving around the pond water.

Cell Size

Cell Theory Origin of Cells All living things are made of cells Cell is the fundamental structural and functional unit of life All cells arise from preexisting cells Origin of Cells On the basis of presence of nucleus cells are divided into two groups: Prokaryotic cells: lack a nuclear envelope Eukaryotic cells: have a nucleus in which the genetic material is separated from the cytoplasm.

Types

Things in common Cell membrane Cytoplasm Genetic Material Energy Currency Enzymes

All cells share certain characteristics. All cells are enclosed by a membrane. All cells are filled with cytoplasm. All cells have DNA. All cells have ribosomes. cell membrane Bacterium (colored SEM; magnification 8800x) cytoplasm

ATTENTION!! Draw this diagram if asked in exam, 3 D structure is not required

PROKARYOTES: First cell type on earth E.g.: Bacteria Generally smaller and simpler than eukaryotic cells Nuclear material is not membrane bound Genomes are less complex Do not contain any membrane bound organelles.

Features shared by all prokaryotic cells: All have a plasma membrane. All have a region called the nucleoid where the DNA is concentrated. The cytoplasm (the plasma-membrane enclosed region) consists of the nucleoid, ribosomes (non- membranous organelles), and a liquid portion called the cytosol.

Specialized features of some prokaryotic cells: A cell wall just outside the plasma membrane. Some bacteria have an outermost slimy layer made of polysaccharides and referred to as a capsule. Some bacteria have flagella, locomotory structures. Some bacteria have pili, threadlike structures that help bacteria adhere to one another during mating or to other cells for food and protection.

Eukaryotic Cells Are larger than prokaryotic cells. Nucleus bound by membrane Animals, plants, fungi have eukaryotic cell type. Possess many membrane bound compartments called organelles Compartmentalization is the key to eukaryotic cell function. Each organelle has a specific role defined by chemical processes.

Representative Animal Cell

Representative Plant Cell

Structure Animal cells Plant cells cell membrane Yes yes nucleus nucleolus ribosomes ER Golgi centrioles no cell wall mitochondria cholorplasts One big vacuole cytoskeleton

http://www.diffen.com/difference/Animal_Cell_vs_Plant_Cell

Cells are Micro Factories!!!

http://www. biologyexams4u. com/2013/03/cell-analogy-cell-as-factory http://www.biologyexams4u.com/2013/03/cell-analogy-cell-as-factory.html#.U6Np4_ldUd0

FACTORY PARTS CELL PARTS FUNCTIONS Shipping/Receiving Department Plasma membrane Regulates what enters and leaves the cell; where cell makes contact with the external Environment. Chief Executive Officer (CEO) Nucleus Controls all cell activity; determines what proteins will be made Factory floor Cytoplasm Contains the organelles; site of most cell activity Assembly line (where workers do their work) Endoplasmic Reticulum (ER) Where ribosomes do their work

FACTORY PARTS CELL PARTS FUNCTIONS Manufacturing machine Ribosomes Build the proteins Finishing/packaging department Golgi apparatus Prepares proteins for use or export Maintenance crew Lysosomes Responsible for breaking down and absorbing materials taken in by the cell Support beams (walls, ceilings, floors) Cytoskeleton Maintains cell shape Power plant Mitochondria/chloroplasts Transforms one form of energy into another

Next Class: Cell Organelles