CELLS

Robert Hooke

• He devised the earliest microscopes that can magnify materials.

• His commemorative work came from a thin slice of cork from the bark of an oak tree.

• He described the perforated and porous surface as honeycomb, later called it as cellulae, using the Latin word small room.

Antonie van Leeuwenhoek

• A Dutch naturalist credited to be the first to study magnified cells.

• He gave the name animalcules, meaning little animals. Because he saw them moving in the pond.

• He was first to observe living cells.

Matthias Jakob Schleiden

A German botanist who said that all plants are made of cells.

Theodor Schwann

• examined animal cells and said all animals are made up of cells.

• Cells are fundamental units of life and the bodies of living organisms are made of cells.

Rudolf Carl Virchow

• German Physician; Stated that all cells come from other cells through the process of cell division.

• All organisms are composed of cells.

• Cells are the smallest and basic units structure and functions in organisms.

• Cells arise from previously existing cells.

Aleksandr Oparin

• proposed that organic molecules might have been assembled in the Earth’s primitive atmosphere in the presence of strong energy (volcanic eruption, meteorites, isotopes, lightning, uv light)

Miller-Urey Hypothesis

• mixture of inorganic compounds in a closed system (strong reducing atmosphere in the primitive Earth) 

• heated and circulated the mixture then applied electric spark 

• Miller (reportedly) got amino acids and organic compounds.

Gases

What was missing from the Miller-Urey experiment?

Organic Chemical evolution

says that the first form of true living cells have evolved from protocells.

Protocells

• are hypothesized to have been formed by the polymerization of organic molecules in heated rocks or in clay.

  • might have been enclosed by a lipid protein membrane and might have possessed an enzymatic activity.

Nucleic acids

are known as the main information-carrying molecules of the cell, as well as leading the process of protein synthesis.

True

What does eu mean?

Karyon

What does karon mean?

Before

What does pro mean?

Prokaryotic Cells

• simple organisms possessing small size, with simple structures

• bacteria, blue green algae, archaeans (bacteria living in extreme environments) 

• reproduce fasts, can be found in air, soil, water, even inside the body of living organisms

Bacteria Cell

Enclosed by a plasma membrane encased with a rigid cell wall

Flagella

• allows locomotion; 360 degrees

• rotation of a whiplike tail moving back and forth can propel the bacteria

Cilia

• Help bacteria cling to surfaces

• Provide mobility

• Short

• used to move substances outside human cell

Nucleoid Region

irregular-shaped region, Contains a circular loop of DNA

Plasmids

• independent circular DNA structure. Plasmid provides the bacteria antibacterial resistance.

Ribosomes

• In cytoplasm whose main function is to synthesize proteins; where proteins are made.’

• The site of protein synthesis

Eukaryotic Cells

• complex type of cell possessed by fungi, plants, animals and protists. 

• it has genetic material (DNA) encased within a nucleus 

• cells are membrane-bound compartments 

• organelles are neatly arranged

Cell Wall

• Found in plants, fungi, and many protists

• surrounds plasma membrane

• rigid responsible for maintaining its shape, especially when cells are exposed to high water influx

•  it provides protection, support and shape to cell

• serves as a barrier separating the cell from external environment.

• secures the cell’s content

• gatekeeper

Plasma Membrane

• semi permeable that allow waste products to pass through while preventing the diffusion of essential products to the external environment.

• regulates the passage of materials into and out of the cell

Cytoplasm

• a gel-like substance making up cell’s internal environment

• viscous fluid containing organelles

Nucleus

• a central genetic region, containing the genetic material in the form of DNA

• control center of cell

• double membrane

• contains –chromosomes –nucleolus

Nucleolus

• most cells have 2 or more

• directs synthesis of RNA

• Dense region where small organelles essential for making proteins are assembled.

Nuclear Envelope

• separates nucleus from rest of cell

• double membrane

• filled with nuclear pore that allow large molecules to pass between the nucleus and cytoplasm.

Endoplasmic Reticulum

• An interconnected network of folded membranes, similar to those of the cell membrane.

• ER membranes are arranged like maze of enclosed spaces with creases and folds

• The lumen and its surface are the sites for production of proteins and lipids.

Smooth ER

• no attached ribosomes and has enzymes that help build molecules which are Carbohydrates and Lipids

• are responsible for the production of lipids and breaking down of drugs and alcohol.

Rough ER

• ribosomes attached to surface, manufacture proteins and not all ribosomes attached to this

• May modify proteins from ribosomes

Golgi Apparatus

• layered stack of membrane-enclosed spaces

• packaging & shipping station of cell

• involved in synthesis of plant cell wall

• proteins are processed, sorted, and delivered. (PSD)

• Its membrane has enzymes to modify proteins.

• Some proteins are stored temporarily in the Golgi apparatus. Some are transported to other organelles some are carried and secreted out of the cell.

Vesicles

• Part that that cannot work without the help of other organelles.

• Proteins that have been manufactured, par of the ER pinches off, to form a small membrane-bound sacs called this, enclosing the proteins.

• will be formed for storage, transport, or secretion.

• short lives and recycled as needed by the cell

• Some of these may turn into lysosomes or vacuoles

Vacuole

• Fluid-filled sac for the storage of materials

• needed by cells that includes water, food

• molecules, inorganic ions and enzymes.

• membrane bound storage sacs

• more common in plants than animals

Central Vacuole

is with watery fluid that strengthens the cell and helps support the entire shape.

Lysosomes

• Round shape membrane bound structure containing chemicals that can break materials in the cell.

Lysozyme

defends the cell from invading bacteria and viruses

Peroxisomes

are membrane-bound organelles in most eukaryotic cells, primarily involved in lipid metabolism and the conversion of reactive oxygen species such as hydrogen peroxide into safer molecules like water and oxygen.

Mitochondria

• supply energy to the cell

• round to oval organelles and two membranes

• Round shape membrane bound structure containing chemicals that can break materials in the cell.

Centriole

• pairs of microtubular structures

• play a role in cell division

Chloroplast

• are organelles that help a plant to convert solar energy to chemical energy.

• carry out photosynthesis, transform solar energy into energy rich molecules the cell can

• use highly compartmentalized

Cytoskeleton

• Made up of small protein subunit, forming long threads of fibers that can crisscross the entire cell

• Framework of flexible network.

• help cell to recognize its content

• help cell to organize its contents and to direct cell’s movement

• filaments & fibers

Microfilaments

• also known as actin filaments

• thinnest among cytoskeleton

• iny flexible that provide mesh work under plasma membrane

Microtubules

Filaments that are lengthy and thick and serve as an anchorage for membrane bound organelles and other cell parts.

Intermediate Filaments

smaller than microtubules, ropelike in appearance

they provide cell tensile strength or ability to stretch without breaking apart

Junctions

All cells joined together by structe are called what?

Plasmodesmata

In plants, adjacent cells function in a coordinated way by coordinating channels

plays an important role of sharing of water, nutrients and chemical messages among plant cells.

Tight Junctions

join two cells tightly together to form leak proof sheet.

Adhesion Junctions

acts like screws together with cytoskeletal fibers to form strong sheets.

Gap Junctions

allow small molecules to flow between neighboring cells

Extracellular Matrix

Act as a glue to bind cell together in tissues and provide mechanical strength

Enables cells to communicate with surrounding cells to signal development, movement and coordination within a tissue sheet.

Capsule

Prokaryotic; this acts as a protective layer made up of polysaccharides lying outside the cell wall.

Fimbriae

• additional smaller bristle-like fibers that grow over the prokaryotic cell’s surface.

• They attach themselves to surfaces

Conjugation Pili

• tubular structures, function for cell to cell communication as well as to pass DNA from one bacterium to the next.

Cholesterol

strengthen the cell membrane, making it more flexible but less fluid, which makes the membrane less permeable to water- soluble substances such as ions or simple sugar.

Carbohydrates

serve as identification tags, enabling cells to distinguish one type of cell from another.

Transport Proteins

extend from the phospholipid bilayer to help materials cross the cell membrane.

Channel Proteins

form tunnels that help cells to import or export needed materials and expel waste.

Cell Recognition Proteins

enable cells to distinguish own cells from otherorganisms, such as pathogens that might invade the body.

Enzymatic Proteins

participate in metabolic reactions such as degenerative and synthetic reactions.

Cytoskeleton Proteins

act as muscle and skeleton to maintain cell shape and motility.

Junction Proteins

assist cell-to-cell adhesion and communication between cell.

Receptor Proteins

facilitate exchange of signals with other cells by changing shape to allow a specific molecule, the ligand (ion molecules which donates a pair of electrons) to bind to it

Fluid Mosaic Model

molecules scattered along the membrane provides variety of different textures and pattern making a mosaic model.

Cytosol

the fluid portion consisting mainly of water and excluding the organelles in it.

DNA

• a long chain of molecules which can be segmented called genes, that contain instructions for making proteins.

• package by a special group of proteins called histones, forming a complex structure called chromatin.

Chromatin

This tightly condenses to form chromosomes.