Cell Biology: Introduction to Cells

TOPIC 1; SUB-TOPIC 1.1; IB BIOLOGY SLY1

Clarity of the viewed object is known as __.

Resolution

INTERNATIONAL SYSTEM OF UNITS (SI) - used to describe size

• 1 centrimetre (cm) = 1/100 (10^-2) metre

• 1 millimetre (mm) = 1/1000 (10^-3) metre

• 1 micrometer (µm) = 1/100 000 (10^-6) metre

• 1 nanometer (nm) = 1/100 000 000 (10^-9) metre 

• 1 metre = 10² cm= 10³ mm = 10⁶ µm= 10⁹ nm

Decreasing Order of Organisms 1

Cells

Decreasing Order of Organisms 2

Organelles

Decreasing Order of Organisms 3

Bacteria

Decreasing Order of Organisms 4

Viruses

Decreasing Order of Organisms 5

Membrane

Decreasing Order of Organisms 6

Molecules

__  is the ratio of the size of the image to the size of the object.

Magnification

Magnifications can be derived from the microscope eyepiece __.

4x, 10x, 40x, 100x

__ are used to improve the sizing and accuracy of the featured sizes.

Scale bars

Cell Theory 1

All Organisms are composed of one of more cells

Cell Theory 2

Cells are the smallest units of life

Cell Theory 3

All cells come from pre-existing cells.

ROBERT HOOKE- 1665

DESCRIBED CELLS AFTER OBSERVING A CORK WITH MICROSCOPE.

ANTOINE VAN LEEUWENHOEK

OBSERVED THE FIRST LIVING CELLS AND REFER TO THEM AS “ANIMALCULES” <-ANIMAL CELLS.

MATTHIAS SCHLEIDEN

BOTANIST WHO STATED PLANTS ARE MADE OF INDEPENDENT , SEPARATE BEINGS CALLED CELLS.

THEODOR SCHWANN-1839

ANIMALS ARE MADE OF CELLS.

LOUIS PASTEUR -1880’S

• Performed experiment supporting the third principle.

• Showed that boiling broth (to sterilize) caused living organisms to NOT reappear “spontaneously”.

• Exposure of cells to pre-existing cells establishes life again.

Functions of Life

• Metabolism

• Growth

• Reproduction

• Response

• Homeostasis

• Nutrition

• Excretion 

METABOLISM

• Chemical reactions which occur within an organism

• Converting energy from one form into another.

metabolism =

catabolism + anabolism

GROWTH

• limited but evident

• Cell Cycle

REPRODUCTION

• Involves hereditary molecules that are passed on to offspring.

• sex cell division (meiosis)

RESPONSE

• Response to STIMULI in the environment is CRUCIAL for the SURVIVAL of the organism.

• Adaptation to the environment.

Hypotonicity

Concentration of ions inside cell which makes water go in.

Isotonicity

Cell is at homeostasis, because there is an equal amount of concentration of ions both in the solute and solvent.

Hypertonicity

Concentration of ions are in the solvent, so water leaves the cell to go outside.

HOMEOSTASIS

• Maintenance of a constant internal environment.

• Control of acid-base and temperature.

What is the optimal temperature of the human body?

37*C or 98.6*F

What temperature is due to infection?

over 104*F

NUTRITION

• Provides a source of compounds with chemical bonds.

• These bonds can be broken down to provide energy necessary to maintain life.

EXCRETION 

• Essential 

• Allows chemical compounds that are not useful for the organism or that may be toxic or harmful to be released.

CELL SIZE

• Volume of a cell is going to determine what metabolic activity takes place inside.

• Surface area determines the rate of exchange of materials with outside.

• Surface area to volume ratio (limits the size of the cell)

• as the surface area to volume ratio increases the size of the cell decreases making this more efficienct.

• As the surface area to volume ratio decreases the cell could potentially take two paths:

  • growth for mitotic division

  • apoptosis (cell death)

• Rate of heat., waste production, rate of resource consumption functions of its volume.

• Chemical reactions occurring inside of cell  and size of the cell affects the rate of reactions.

• Surface of cell controls what moves in or out of the cell. 

DIFFERENTIATION

• Cells can take on a specific function so the organisms can grow in complexity as well as size.

• Occurs due to expression of genes but not others.

GENE EXPRESSION

• Genes (segments) are located in DNA of Chromosomes which can be expressed during differentiation to produce certain types of cells. 

• CELLS contain all genetic information required to produce an entire organism 

  • It will only become a specific cell depending on which segment of the DNA is active. 

SPECIALIZED CELLS 

• Some cells reduce their ability to reproduce after specialization or completely lose it.

  • Nerve cells

  • Muscle cells 

• Other cells gain their ability to reproduce at a rapid pace throughout their lives.

  • Epithellial cells (ex. Skin)

CELL BEHAVIOR

• This depends on the same genetic make up which all cells contain.

• Muscle cells and pancreatic cells contain the same genes.

• Certain genes are not expressed in some cells.

  • Ex: Stratified Epithelial cells do not express a gene for production of insulin as supposed to Pancreatic cells.

DIFFERENTIATION IS THE PROCESS OF __?

CELLS BEING SPECIALIZED.

Emergent Properties

• Different cell types interact with each other to allow more complex functions tot take place.

• Results from reproduction of cells and differentiation.

CANCER CELLS 

• Undergo extremely rapid reproduction (proliferation) with a very little improper differentiation

• Tumors

  • Result of mass of cells

  • Spread very easily

  • Take control of vital organs blood supply

STEM CELLS 

• Cells found within an organism which possess the ability to divide and differentiate into different cell types.

• 1980’s: Scientist discovered Pluripotent and embryonic stem cells in mice.

• Found cells have the ability to differentiate or form a complete organism.

• Some of these cells remain as stem cells (do not divide to form tissue) and were the spark of stem cell research.

• Scientists found the possibility to utilized these cells to treat specific diseases

  • A problem discovered was stem cells cannot be distinguished by appearance but on the basis of their behavior.

Where are PLANTS- MERISTEMATIC TISSUE located?

in the root and stem tip of plants containing cells which are capable of reproducing at a fast pace into new to produce different types of tissue.

Who utilize PLANTS- MERISTEMATIC TISSUE?

by Gardeners to produce new plants due to their function.

EMBRYONIC STEM CELLS OR PLURIPOTENT

• Are unique in their potential versatility to differentiate into all body’s types.

• Some adult tissues contain different form of stem cell which can only differentiate into cells associated with that tissue. (tissue specific stem cell- also known as MULTIPOTENT)

  • EX: bone marrow contains stem cells that can form all the different types of blood cell, not muscle cells or liver cells.

STEM CELLS DIFFER FROM OTHER CELLS because they are

unspecialized

STEM CELLS DIFFER FROM OTHER CELLS because they divide

repeatedly to make large number of new cells

STEM CELLS DIFFER FROM OTHER CELLS because they differentiate 

into several types of cells

STEM CELLS DIFFER FROM OTHER CELLS because they contain a

large Nucleus relative to the volume of the cytoplasm.

STARGARDT’S DISEASE is treated with __ in early stages.

stem cells

STARGARDT’S DISEASE is caused by

the passing of a gene to offspring coding for a defect in Vitamin A.

Vitamin A is

essential for the light sensitive cells in the retina to function properly.

First ___ patient loses central vision with Stargardt’s Disease.

20 years

After central vision is lost, ___ is lost which then turns into complete blindness.

peripheral vision

STARGARDT’S DISEASE research in March of 2010 includes

research utilizing stem cells to protect and regenerate photoreceptors found in the retina.

STARGARDT’S DISEASE is treated with

human embryonic stem cells.

pluripotent stem cells are able to differentiate into

any other cell

STEM CELL RESEARCH began in

the 1980’s

Stem Cell Research also includes

• Growth of stem cells to replace damaged tissue or diseased (alzheimers)

• Discarded embryos from IVF clinics (debate of it being unethical)

• Destruction of embryo to obtain stem cells (morally Unethical)

• Other forms of research (less controversial)

  • Removal of cells from bone marrow

  • Bone marrow transplants to help in Leukemia patients

multipotent stem cells can only differentiate into

cell types within a single particular tissue