- Mid 1600's Robert Hooke observed and described cells in cork
- Late 1600's Antony van Leeuwenhoek observed sperm and microorganisms
-1820's Robert Brown observed and named nucleus in plant cells
Who developed cell theory?
1. Living organisms are composed of one or more cells
2. Cell is the smallest unit having characteristics of life
3. new cells arise from the growth and division of single cells
3 Main Features of Cells
- Plasma membrane
- Region where DNA is stored
An optical instrument with lenses that refract visable light to magnify images and project them into a viewers eye or onto photographic film.
An instrument that focuses an electron beam through or onto the surgace of a specimin
An electron microscope achieves a hundred fold greater resoloution than a LM
A microscope that uses an electron beam to study the surface architecture of a cell or other specimin
A microscope that uses an electron beam to study the internal structure of thinly sectioned specimens.
The membrane that sets a cell of from its surroundings and acts like a selective barrier to the passage of ions and molecules into and out of the cell
Consists of phospholipid bilayer in which molecules of protien and cholesterol are embedded
Everything inside of a cell between the membrane and the nucleus
consists of a semi fluid medium and organelles
Type of cell lacking a membrane enclosed nucleus and other membrane enclosed organelles
found only in bacteria and archaea
a membrane enclosed structure with a specialized function within a cell
a type of cell that has a membrane enclosed nucleus and other membrane enclosed organelles
all orgamisms except bacteria and archaea are composed of eukaryotic cells
An atoms central core containing protons and neutrons
the genetic control center of a eukaryotic cell
Protective layer external to the plasma membrane in plant cells, bacteria, fungi, and some protists
protects the cell and helps maintain its shape
a double membrane perforated with pores that encloses the nucleus and seperates it from the rest of the eukaryotic cell
a network of membranes inside and around a eukaryotic cell related either through direct physical contact or by the transfer of membranous vesicles.
a network of interconnected membranous tubules in a eukaryotic cell's cytoplasm
smooth ER lacks ribosomes
a network of interconnected membranous sacs in a eukaryotic cell's cytoplasm
rough ER membranes are studded with ribosomes that make membrane protiens and secretory protiens
a sac made of membrane in the cytoplasm of a eykaryotic cell
tissue made up ofneurons and supportive cells
tissue consisting of long muscle cells that are cabaple of contracting when stimulated by nerve impulses.
the most abundant tissue in a typical animal
tissue consisting of sparse population of cells held in an abundant extracellular matrix which they produce.
a sheet of tightly packed cells lining organs, body cavities, and epithelial surfaces
a shor cellular appendage specialized for locomotion.
formed from a core of nine outer doubled microtubles and two single microtubules covered by a cell's plasma membrane
A long cellular appendage specialized for locomotion
The flagella of prokaryotes and eukaryotes differ in both structure and function
structure within the nucleus of a eukaryotic cell where ribosomal RNA is made and assembled with protiens imported from the cytoplasm to make ribsomal subunits
An organelle foundin plants and photosynthetic protists that absorbs sunlight and uses it to drive the synthesis of organic molecules (sugars) from carbon dioxide and water
a network of protein fibers in the cytoplasm of a eukaryotic cell includes microfilament, intermediate filaments and microtubules
The complex of DNA proteins that constitutes eukaryotic chromosomes
often used to refer to the diffuse very extended form taken by chromosomes when a cell is not dividing
(model and description)
a description of membrane structure depicting a cellular membrane as a mosiac of diverse protein molecules embedded in a fluid bilayer made of phospholipid molecules.
The spontaneous tendency of a substance to move down its concentration gradient from where it is more concentrated to where it is less concentrated.
the passage of a substance through a specific transport protein across a biological membrane down its concentration gradient.
-An increase or decrease in the density of a chemical substance in an area.
- Cells often maintain concentration gradients of ions across their membranes
- when a gradient exists, substances tend to move from where they are more concentrated to where they are less concentrated.
the movement of a substance across a bilogical membrane against its concentration gradient, aided by specific transport proteins and requiring input of entergy (often as ATP).
Exocytosis & Endocytosis
Exo- the movement of materials out of the cytoplasm of a cell by the fusion of vesicles with the plasma membrane
Endo-cellular uptake of molecules or particles via formation of new vesicles from the plasma membrane
cellular eating- a type of endocytosis wherby a cell engulfs macromolecules other cells or particles into its cytoplasm
Hypertonic, Isotonic, Hypertonic Solutions
-hypo, in comparing two solutions- the one with the greater concentration of solutes. Cells in such a solution will lose water to their surroundings.
-iso, a solution having the same solute concentration as another solution, thus having no effect on passage of water in or out of a cell
-hyper, in comparing two solutions, the one with the lower concentration of solutes, cells in such a condition will take up water from their surroundings.
The diffusion of water across a selectively permeable membrane.
is the main pressure of the cell contents against the cell wall in plant cells and bacteria cells, determined by the water content of the vacuole, resulting from osmotic pressure, i.e. the hydrostatic pressure produced by a solution in a space divided by a semipermeable membrane due to a differential in the concentration of solute.
the ability of a solution surrounding a cell to cause that cell to gain or lose water
stored capacity to perform work, organisms store chemical energy in organic molecules
energy of motion, energy is transferred
Can be transfered or transformed but not destroyed
Energy flow through life is one way
First Law of Thermodynamics
The principle of conservation of energy. Energy can be transferred and transformed, but not created or destroyed
Second Law of Thermodynamics
The principle wherby every energy conversion reduces the order of the universe, increasing its entropy. ordered forms of energy are at least partly converted to heat.
A measure of disorder. one form of disorder is heat, which is random molecular motion
in cellular metabolism the use of energy released from an exergonic reaction to drive an endergonic reaction.
- powers all cellular work
- consists of adenine, a nitrogenous base, and ribose (five carbon sugar)
- there are 3 phosphate tails all negatively charged which makes them unstable and easily broken in hydrolysis
- when the third group is broken and the ATP is released it then becomes ADP
- Hydrolysis is an exergonic reaction
when the third phospate is transfered from the ATP
3 types of cellular work
-proteins that function as bilogical catylists increasing the rate of reaction without being consumed by the reaction
-they speed up the reaction by lower the EA barrier
a non protein helper that is organic (most vitamins)
-region in the substrate where the enzyme fits.
-typically a groove or socket formed by amino acids
a specific reactant (like sucrose) than an enzyme reacts to
-chemical that interferes with an enzymes activit
-if it covalently bonds it is irreversible
-if not it can be broken
-reduces the enzymes productivity by blocking the substrates from entering the active site
-combatted by increasing the amount of substrate increases the odds they will bond.
-doesn't enter the active site but binds to some other spot on the enzyme which changes the shape of the enzyme and makes the active site no longer work
regulates metabolism by blocking reaction because of over production
starting materials in a chemical reaction
product of a chemical reaction
is whats left after the reaction occurs- some combine and some are left in peices
Describe the fluid mosiac of a cell membrane and what the structure of phospholipids do
The fluid mosiac is basically the cell wall and its components
- phospholipids are double bonded fatty acids whose tails don't pack tightly because of their kinks, because of this the cell membrane stays fluid.
-cholesterol in the fluid mosiac helps it maintain its shape in warm temperatures but fluid in cold
-integrins are proteins that help a cell with fromawork strength
-carbs on the outside of cells help other cells identify function and type
1st law of thermodynamics
you can't create or destroy energy, just transfer and convert
ex: coal, light bulb, green plants preforming phytosynthesis
2nd law of thermodynamics
some energy becomes unstable during conversion and can't be used. this becomes heat/random thermal energy
ex: heat from combustion, heat from ATP creation and breakdown