Chapter 5 (The Cell and the Hierarchy of Life)

Robert Hooke

Robert Hooke

he first coined the term cell; he observed thin slices of cork in the microscope

schleiden, schwann, virchow

they fully understood the importance of cells in the living matter and concluded the "cell theory"

prokaryote

resemble one another in form, having little internal organization and a strong cell wall encasing their exteriors; ex. Bacteria and cyanobacteria

eukaryote

any cell or organism that possesses a clearly defined nucleus; ex. plants and fungi

cell membrane, cytoplasm and nucleus

3 components of cell

cytoplasm

gelatinous liquid that fills the inside of a cell; the living matter within the cell, excluding the nucleus

hyaloplasm

fluid and jellylike substance found in cytoplasm

karyolymph

a clear liquid in the cell nucleus in which the nucleolus and chromatin and other structures are dispersed

chromatin

thread-like materials that form a network within the nucleus; the readily stainable substance of a cell nucleus consisting of DNA and RNA and various proteins

nucleolus

the aggregate of granules made of ribonucleic acid (RNA) and located inside the nucleus.

cell membrane

a thin membrane enclosing the cytoplasm of a cell; gives form to the cell and controls the passage of materials in and out of cell.

cell wall

in plants; found next to the cell membrane; provides support and may even keep the plant cells from bursting in hypoosmotic environments

ribosome

synthesize protein molecules that may be used to build cell structures or to function as enzymes.

endoplasmic reticulum

series of membranous channels that traverse the cytoplasm of most eukaryotic cells.

rough er

ribosomes are attached to ER that gives them the rough appearance; associated with active protein synthesis process

smooth er

does not contain ribosomes; involved in the synthesis and transport of lipids or detoxification of a variety of poisons within the cell

golgi apparatus

responsible for the storage, modification and packing of materials produced for secretory export; also involved in the formation of lysosomes and other transport vesicles of the cell.

mitochondria

releases energy from food molecules and transform energy into usable ATP which happens during cellular respiration

chloroplast

responsible in the conversion of light energy to the chemical energy of sugars in the photosynthesis process in plants

cristae

double-walled membranous sacs with folded inner partitions

thylakoids

double membrane organelles with inner folds

lysosome

responsible in the digestion of nutrients, bacteria, and damaged organelles

apoptosis

a type of cell death in which the cell uses specialized cellular machinery to kill itself

peroxisome

contain enzymes that detoxify harmful molecules; enzymes produced are involved in the oxidative deamination of amino acids and break down of hydrogen peroxide

vacuole

membranous sacs that store and release various substances within the cytoplasm; responsible for cell’s enlargement and water balance

cytoskeleton

used in the maintenance of the cell shape

centrosome

a small region of cytoplasm adjacent to the nucleus; contains the centrioles (animal cells only) and serves to organize the microtubules

cilia and flagella

are minute cytoplasmic projections (animal cells only); responsible to move particles along cell surface or to move the cell itself

fibrils and microtubules

are thin, hollow tubes that support the cytoplasm and transport materials within the cytoplasm

intracellular fluid

the inside environment of a cell is called the _; referred to all fluid contained in cytosol, organelles and nucleus

extracellular fluid

the environment outside a cell is called the _; Plasma, the fluid part of blood, is the only compartment that links all cells in the body

cytosol

the aqueous part of the cytoplasm within which various particles and organelles are suspended

phospholipid bilayer

plasma (cell) membrane separates the inner environment of a cell from the extracellular fluid. It is composed of a fluid _.

cholesterol, proteins, glycolipids and glycoproteins

4 other molecules found in the membrane

nuclear envelope

separates the contents of the nucleus from the contents of the cytoplasm

Nuclear pores

found in the envelope are small holes that control which ions and molecules (for example, proteins and RNA) can move in and out the nucleus

Transport Vesicles

Move substances between compartments inside cells

Secretory Vesicles

Join with cell membrane to release contents, such as mucus to ECF

osmosis

diffusion of molecules through a semipermeable membrane from a place of higher concentration to a place of lower concentration until the concentration on both sides is equal

diffusion

the process in which there is movement of a substance from an area of high concentration of that substance to an area of lower concentration

simple diffusion

molecules move down their gradients through the membrane; does not require the assistance of membrane proteins.

Facilitated diffusion

_ is diffusion that is helped along (facilitated by) a membrane transport channel

primary active transport

Transport that directly uses ATP for energy to transport all species of solutes across a membrane against their concentration gradient.

Secondary active transport

_ moves multiple molecules across the membrane, powering the uphill movement of one molecule(s) (A) with the downhill movement of the other(s) (B)

symporter

transport molecules in the same direction.

Antiporters

transport molecules in opposite directions

Fermentation and Respiration

two major strategies for energy conservation in chemoorganotrophs

Fermentation

anaerobic catabolism; an organic compound is both an e- donor and an e- acceptor

Respiration

an/aerobic catabolism; an e- donor is oxidized with O2/substitute as terminal e- acceptor

Glycolysis

Embden–Meyerhof–Parnas pathway, first step, common to all organisms, takes place in the cytoplasm, converts glucose a 6-carbon molecule into 2 3-carbon molecules called pyruvate, net gain of 2 ATP per 1 molecule of Glucose

Alcoholic Fermentation

starts with glycolysis (net gain 2 ATP), lost Carbon is given off as carbon dioxide, both carbon dioxide and ethanol is release in to the environment as waste product

Lactic acid Fermentation

starts with glycolysis (net gain of 2 ATP), allows glycolysis to continue with a small gain of ATP in addition to the ATP generated through aerobic pathway

Aerobic Respiration

also begins with glycolysis (net gain of 2 ATP)

Transition Reaction

each pyruvate molecule (3-C) loses a carbon, carbon is given off as carbon dioxide, acetyl (2-C) molecule is produced, acetyl combines with coenzyme A forming acetyl-coA

Citric acid cycle

also known as Tricarboxylic acid cycle, 2 carbon molecules are released as carbon dioxide,

▸begins and ends with the same molecule, allows cycling ▸ generates 1 ATP per cycle ( 2 ATP per glucose molecule since there are 2 acetyl-coA produced per glucose molecule) ▸ generates NADH and FADH2

Electron Transport Chain

stage where most ATPs from glucose are produced

involves electron carriers that pass the electrons from one to another