Cytology  Objectives: –Compare prokaryotic and eukaryotic cells –Investigate the anatomy (structure) and physiology (function) of a typical cell –Compare animal and plant cells

Cytology  Cytology : is the study of the structure and function of cells.  Cytoplasm : is the area of space outside the nucleus but which is contained within the cell membrane. It contains the organelles and fluid.  The organelles are tiny structures in the cytoplasm which perform various jobs for the cell.  The fluid part of the cytoplasm is called the cytosol.  Cell Cell

Nucleoplasm  Nucleoplasm : is the area of space found inside the nucleus.

Prokaryotic Cells  They lack a nuclear membrane as well any other membrane covered organelles in their cytoplasm.  Considered to be “Primitive Cells”  Example : Bacteria & Blue-Green Algae

Prokaryotic Cell

Eukaryotic Cells  They possess a nuclear membrane as well as membrane bound organelles in their cytoplasm.  Example : Plant & Animal Cells

Eukaryotic Cell

The Cell Structure & Function

The Nucleus  is the computer or control center of the cell.  contains the genetic material of life DNA (Deoxyribonucleic acid).  Long chains of DNA form Chromatin.  Short sections of DNA along a piece of chromatin form Genes.  The Human Genome consists of about 30,000 Genes.

The Nucleus  Let’s draw a cell that we will add to as the unit continues.

 Nucleolus / Nucleoli (plural) : is a dark spherical structure that is the site of ribosome formation.  Nuclear Membrane or Envelope surrounds the nucleus  Nuclear pores control what moves in and out of the nucleus

DNA Structure The building blocks of DNA are called Nucleotides A nucleotide consists of a : 1. phosphate group 2. sugar 3. nitrogen base : 4 types adenine (A) thymine (T) cytosine (C) guanine (G) DNA consists of two nucleotide chains connected together to form a twisted ladder called a Double Helix

Nucleotide Structure  Nucleotides look like this:

Nucleotides  Draw a DNA strand with the base sequence A- C-T on the left side. Make the top left the 5’

A C T T G A

Organelles  Look in your textbook ( ) to find the function and appearance of the following.  Record your finding in your notes.  Ribosomes  Endoplasmic Reticulum (Rough and Smooth)  Golgi Apparatus  Lysosomes

Organelles  Ribosomes : tiny non-membrane bound structures that synthesize proteins.  Proteins : composed of long chains of amino acids, makes up 75% of a cell’s dry weight.  Proteins are important because they :  (1) provide the main structural component of you  (2) act as Hormones, which are chemical messangers  (3) act as Enzymes, which control all chemical reactions in your cells

 Rough Endoplasmic Reticulum (RER): membrane bound canals with a rough appearance due to ribosomes  Smooth Endoplasmic Reticulum (SER): membrane bound canals that lack ribosomes, hence the smooth appearance. Lipids (fats) are transported through the SER

Ribosomes and RER/SER

 Golgi Apparatus / Golgi Bodies / Golgi Complex:  Is often referred to as the “cell’s post office”.  Proteins from the RER travel to Golgi, where they are : (1) sorted, (2)addressed, & (3) packaged into membrane bound vesicles called Lysosomes  Lysosomes Lysosomes

Golgi Bodies and Lysosomes

RER/Golgi Bodies  RER/Golgi Bodies RER/Golgi Bodies RER/Golgi Bodies

Try this!  1. Cells that lack membrane bound organelles are called _____.  2. Cells with a defined nucleus are called _____.  3. The openings in the nuclear envelop are called _____.  4. Long thin strands of DNA are called _____.  5. Coiled up strands of DNA are called _____  6. Dark spheres in the nucleus where ribosomes are produced are called _____.  7. Canal network throughout the cell used for transporting material is called _____.  8. The term ______ is used to describe ER with ribosomes attached.  9. Protein are produced at the site of ______.  10. Vesicles that carry digestive enzymes are called _____.  11. The “post office” of the cell is the _____.  12. The canal network that transports fats is called _____.

Let’s Add to our Developing Cell

Back to your Textbook  Read ( ) about the following organelles and describe their function in your notes:  Vacuoles  Mitochondria  Chloroplasts  Cytoskeleton  Microfilaments  Microtubules  Centrioles

…another organelle  Vacuole – special vesicle that store water (water vacuole) or stores food particles (food vacuole)  Water vacuoles are small in animal cells. (2 below) Number in your notebook from 1 to 13 and identify the structures below.

Mitochondrion  Mitochondria (plural) : is a membrane bound oval shaped organelle that function as the cell’s “power plant”.  This is where glucose is broken down to release energy during a chemical reaction called “Cellular Respiration”  This energy released is stored in energy carrying molecules called ATP.  It takes 36 ATP molecules to store the energy released from the break down of one glucose molecule.

Cellular Respiration C 6 H 12 O 6 + 6O 2 + enzyme 6CO 2 + 6H 2 O + Energy This energy will be stored in 36 ATP molecules. Only eukaryotic cells have mitochondria. Mitochondria have their own DNA! ?? Mitochondria have their own DNA! ?? (Scientists think that the mitochondria was once a cell that was engulfed by another cell producing the first Eukaryotic cell)

Anaerobic Respiration  - Breaking down glucose without the use of O 2  (+) quick supply of energy  (-) small amount of energy/build up of Lactic Acid  C 6 H 12 O 6 2 C 3 H 6 O 3 + E  Only 2 ATP molecules are needed to store this energy

Cytoskeleton  Composed of protein found in the cytoplasm and provides a support system for the cell

Microfilaments  Composed of actin and makes up most of the cytoskeleton.

Microtubules  Composed of small hollow protein tubes called tubulins  Make up cilia and flagellum which are used for cellular locomotion

…another organelle  Centrioles – 2 bundles of rod-shaped fibres that function in cell division  Only found in Animal cells

Animal Cell Smooth endoplasmic reticulum Ribosome (free) Ribosome (attached) Golgi apparatus Mitochondrion Rough endoplasmic reticulum Cell membrane Nucleus Nuclear envelope Nucleolus Centrioles

Plant Cells  Contain “Plastids”, special organelles in plants  A) Chloroplasts – site of photosynthesis  B) Amyloplasts – found in the roots cells of plants and store starch

Chloroplast  Found autotrophs  Contain the green pigment chlorophyll.  They are involved with the process of Photosynthesis.  Photosynthesis is exactly the opposite chemical reaction compared to Cellular Respiration

Photosynthesis 6CO 2 + 6H 2 O + sun light C 6 H 12 O 6 + 6O 2 The glucose created from photosynthesis can now be broken down through Aerobic Respiration to release energy that will be stored in 36 ATP molecules. The glucose created from photosynthesis can now be broken down through Aerobic Respiration to release energy that will be stored in 36 ATP molecules. Chloroplasts also have their own DNA ? Chloroplasts also have their own DNA ?

What’s The Difference? Animal Cell Plant Cell Do not have a cell wall Possess a cell wall made of cellulose Do not have plastids like chloroplasts Possess plastids like chloroplasts Possess centrioles used in cell division No centrioles but can still do cell division Possess small vacuoles Possess large vacuole 90% of cell’s volume Round to irregular in shape Rectangular in shape due to cell wall

Plant Cell Nuclear envelope Ribosome (free) Ribosome (attached) Mitochondrion Golgi apparatus Vacuole Nucleolus Nucleus Smooth endoplasmic reticulum Rough endoplasmic reticulum Cell wall Cell membrane Chloroplast

Animal and Plant Cells  Let's Compare Let's Compare Let's Compare

 Animal and Plant Cell Animal and Plant Cell Animal and Plant Cell