Cell Theory

spontaneous generation

a theory in where people believe that living organisms could spontaneously arise from non-living matter

Francesco Redi

in the 17th century, he conducted a simple yet powerful experiment using meat and jars. he placed the meat into two set of jars, one covered and one open. where flies appeared and left magots in the open jar.

Lazzaro Spallanzani

In the 18th century he experimented by boiling broth in sealed containers. No microorganisms appeared in the sealed broth, proving that boiling killed the life forms and that new ones didn’t just arise from the broth

Biogenesis

In Spallanzani’s work, this was highly hinted. It also means that life comes from pre existing life, what terminology was this?

Louis Pasteur

In the 19th century, He used a special flask with a curved neck that allowed air in but prevented dust and microbes from reaching the broth inside. The broth remained free of microorganisms until the flask was tilted, allowing dust to reach the broth, which then became contaminated.

Louis Pasteur

Whose experiment showed that clearly showed that microorganisms came from other microorganisms in the air, not from the broth itself?

1. All organisms are composed of one or more cells.

2. Cells are the smallest and basic units of structure and function in organisms.

3. Cells arise only from previously existing cells

what were the first three postulates / tenets involved in the cell theory?

Antonie van Leeuwenhoek

He is the first to see living organisms under the microscope, he termed this organisms “animalcules”

Schleiden and Schwann

Who developed the first two tenets of the cell theory?

Rudolf Virchow

He discovered the third tenet of the cell theory.

4

How many tenets were added to the modern cell theory?

1. All energy flow occurs within the cell

2. Cells contain genetic material passed to daughter cells during cell division

3. All cells are similar in their chemical composition

4. Activities of the organism are a result of combined actions of individual cells

What were the four other tenets added to the cell theory?

All energy flow occurs within the cell

This postulate emphasizes that all the biochemical processes that provide energy and build the cellular components—collectively known as metabolism—occur within the cells.

Cells

are the sites of energy conversion and usage, such as in cellular respiration and photosynthesis.

Cells contain genetic material passed to daughter cells during cell division

This tenet says that cells contain DNA that is responsible for hereditary information. This is then passed from parent cells to daughter cells, to ensure the continuity of life.

All cells are similar in their chemical composition

This postulate asserts that while there is vast diversity in cell types and organisms, the chemical composition of cells is fundamentally similar. Cells across different species share basic molecular components like nucleic acids, proteins, lipids, and carbohydrates, indicating a common origin of life.

Activities of the organism are a result of combined actions of individual cells

This postulate highlights that the functions and activities of a multicellular organism result from the collective activities of its individual cells. Each cell's performance contributes to the organism’s overall health, growth and function.

Antonie van Leeuwenhoek

He discovered bacteria, and was the first to observe it along with protists.

Robert Hooke

He initiated the study of cell structure.

Free Cell Formation

What theory of Schleiden was rejected?

Carl Zeiss and Ernst Abbe

They developed modern compound microscope with improved optics and revolutionized cell study.

Camillo Golgi

They discovered “golgi apparatus”

Golgi Apparatus

This is an organelle involved in cellular transport and secretion.

Santiago Ramón y Cajal

he pioneered the neuron theory that showed that the nervous system consists of discrete individual cells (neurons)

Robert Brown

They identified the cell nucleus, which is essential for housing genetic materials in eukaryotic cells.

James Watson and Francis Crick

it is known that there are four people who contributed to the double helix structure of the DNA, however- who were the actual first two pioneers?

Lynn Margulis

They proposed the endosymbiotic theory, which suggests that certain organelles, like mitochondria, originated from symbiotic bacteria engulfed by eukarotyic cells.

Rita Levi-Montalcini

Discovered nerve growth factor (NGF) showing that cells produce specific molecules to regulate cell growth and differentiation.

Shinya Yamanaka and John Gurdon

Discovered cellular reprogramming which proved that specialized cells can be converted back into stem cells, eventually opening up new possibilities in regenerative medicine.

unicellular organism

what type of cell depends upon just one cell for all of its functions

multicellular organism

what type of cell has cells specialized to perform different functions that collectively support the organism

Unicellular organisms

this type of cell, the _____ include bacteria, protists, and yeast.

Unicellular organisms

form the base of food chains and are crucial for nutrient cycling.

Phytoplankton

what perform photosynthesis in aquatic environments, and soil bacteria, which decompose organic matter?

Unicellular organisms

Beneficial ____ aid in digestion, vitamin synthesis, and immune system support. An example of this is e-coli (Escherichia coli) which helps for digestion in the human gut.

fermentation

Unicellular organisms are used in industrial processes like ____ and in the production of pharmaceuticals.

False, unicellular.

Saccharomyces cerevisiae (yeast) is a type of multicellular organism which is commonly used in baking, brewing and such. it is also the bacteria needed in producing insulin. true or false?

True

Unicellular organisms contribute to oxygen production and the breakdown of pollutants. An example of this is the cyanobacteria. true or false?

True

Some unicellular organisms are pathogens, which help in studying disease mechanisms and developing treatments. True or false?

Multicellular organisms

These cells are composed of more than one cell, with groups of cells differentiating to take on specialized functions.

labour

The division of ____ is seen in multicellular organisms. These cells are differentiated in the earlier stage of cell division.

Nerve cells

These cells have appendages called dendrites and axons that connect with other nerve cells to move muscles, send signals to glands, or register sensory stimuli.

Outer skin cells

This cells form flattened stacks that protect the body from the environment.

Muscle cells

these cells are slender fibers that bundle together for muscle contraction.

unicellular organism

with the descriptions in the table, can you tell which cell organism is it?

multicellular organism

with the descriptions in the table, can you tell which cell organism is it?

Prokaryotes

are unicellular organisms without a true nucleus or membranebound organelles. (Bacteria and Archaea)

Eukaryotes

have a true nucleus containing the cell's DNA and possess membrane-bound organelles. (Plant cells, animal cells, fungi, and protists.)

Prokaryotic Cells

They have a Cell membrane, cell wall, cytoplasm, ribosomes, nucleoid region (DNA). What type of cell is this?

Eukaryotic Cells

This type of cell contains Nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, chloroplasts (in plant cells), and more complex cytoskeleton.

Prokaryotes

They typically reproduce through binary fission, a simple form of asexual reproduction.

Eukaryotes

They Can reproduce asexually through mitosis or sexually through meiosis, involving complex processes and cell division.

Prokaryotes

They generally have a single, circular DNA molecule located in the nucleoid.

Eukaryotes

They have multiple, linear chromosomes contained within a membrane-bound nucleus.

Prokaryotes

They exhibit a wide range of metabolic activities, including photosynthesis, nitrogen fixation, and anaerobic respiration.

Eukaryotes

They are more specialized in their metabolic processes, often relying on organelles like mitochondria and chloroplasts for energy production

Prokaryotes

Their role in ecological applications are mainly nitrogen fixation, decomposition, and as pathogens or symbionts.

Eukaryotes

They function in complex organisms, ecosystems, and applications in biotechnology and medicine.

plant cell

what kind of cell is this?

animal cell

what kind of cell is this?

plant cell

what cell is this?

animal cell

what cell is this?

Specialized Cells

Your body contains over 200 different types of this. Each type is adapted to do a particular job well and has developed special features to do it.

Muscle Cells

• key function-contraction.

• long fibres, 1–40 mm long

• Many mitochondria for high energy demands

• up to 100 nuclei

• contain special cylindrical organelles called myofibrils that are involved in contraction.

Sperm Cells

These cells are specialized for reproduction and their function is to transport the male DNA to the egg

egg cell

The function of this is to carry the female DNA and to provide nourishment to the embryo during the first stages of pregnancy.

Nerve cells

The function of the nerve cell is to carry nerve impulses around your body.

Root Hair Cell

The function of the this is to absorb minerals and water from the soil.

It has:

• A large surface area to absorb lots of water

• Thin cell wall to allow water to pass through easily

  • Doesn't contain any chloroplasts

Red Blood Cell

The function of this is to carry oxygen from the lungs to the body.

It has:

• A large surface area to volume ratio

• Contains haemoglobin which carries oxygen

• Has no nucleus to make room for more oxygen

Ciliated Epithelial Cell

The function of these is to line the surface of organs. These cells move substances in one direction. These can be found along the lining of the airways. They move mucus.

Palisade Cell

Their function is to carry out photosynthesis. They are found at the top surface of a leaf.

Palisade Cell

Tall and has a large surface area to catch as much sunlight as possible, Packed with chloroplasts to absorb sunlight. What specialized cell is this?

Cell Differentiation

These are cells developing into different cell types.

DNA

This determines what the cell will be.