Anatomy cells test study hard

Robert Hooke (1665)

Discovered cells

Leeuwenhoek- 1695

observed living microorganisms

Schwann (1839)

all animals are made of cells

Schleiden (1839)

All plants made of cells

Virchow (1855)

All cells come from other cells

cell theory

idea that all living things are composed of cells, cells are the basic units of structure and function in living things, and new cells are produced from existing cells

Microscopy

the history of cytology is tied to the development of the microscope

light microscope

microscope that uses a beam of light passing through one or more lenses to magnify an object
x=1200
ability to distinguish between two object

transmission electron microscope

An electron microscope used to study the internal structure of thin sections of cells
x=100,000
specimens have to be prepared and cant be living

scanning electron microscope

a microscope that produces an enlarged, three-dimensional image of an object by using a beam of electrons rather than light

Cell fragmentation

technique in which cells are broken into pieces and the different cell parts are separated to study

Radioactive isotope labeling

Use techniques to get radioactive isotopes of various elements into a cell and then study how the cell uses that element

plasma membrane

The membrane at the boundary of every cell that acts as a selective barrier, thereby regulating the cell's chemical composition.

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

Nucleus

Control center of the cell large membranous structure near the center of the cell

Why are cells so small?

smaller cells have more surface area across which to pass oxygen, nutrients and waste materials

Cell membranes

are thin coverings that surround cells

plasma membrane (cell membrane)

Flexible, selectively permeable (having pores or openings) boundary that helps control what enters and leave the cell.

fluid mosiac model of cell membrane

the membranes separates internal cytoplasm from external environment of the cell; cholesterol helps the fluidity within the membrane

primary structure

double layer of phospholipids
phosphate heads are hydrophilic
tails are hydrophobic
water cant pass-through
channel proteins which are embedded in the membrane help control movement of materials into and out of the cell

cholesterol molecules

embedded in the interior of the bilayer to stabilize the membrane

Glycoproteins

have carbohydrates attached and serve as cell identifiers

receptor proteins

react to specific chemicals and cause changes within the cell

passive transport

Requires NO energy, Movement of molecules from high to low concentration, Moves with the concentration gradient

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.
continues to equilibriums
-membrane channels are pores through which specific ions or small water-soluble molecules can pass
-gases also move by diffusio

Osmosis

Diffusion of water through a selectively permeable membrane

dialysis

The diffusion of small solutes through a selectively permeable membrane.

filtration membrane

three barriers through which fluid passes

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

Opposite of diffusion

movement of molecules from low concentration to high concentration

endocytosis

the process by which a cell takes material into the cell by infolding of the cell membrane
-without passing through membrane

Phagocytes

a type of cell within the body capable of engulfing and absorbing bacteria and other small cells and particles.

Pinocytosis

A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.

Exocytosis

release of substances out a cell by the fusion of a vesicle with the membrane.
-also is how the smooth endoplasmic recticulum is able to add new material to the plasma membrane

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended
-organelles are suspended in cytoplasm and attached to the cytoskeleton

Cytosol

The semifluid portion of the cytoplasm.

Endoplasmic Reticulum

A cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.

Rough Endoplasmic Reticulum

System of internal membranes within the cytoplasm. Membranes are rough due to the presence of ribosomes. functions in transport of substances such as proteins within the cytoplasm

Smooth Endoplasmic Reticulum

An endomembrane system where lipids are synthesized, calcium levels are regulated, and toxic substances are broken down.
-helps detoxification of poisons

Ribosomes

site of protein synthesis
-many are attached to rough ER others are free in the cytoplasm

Attach to the mRNA and move along it adding amino acids
-subunits are composed of rRNA and protein
-Attached ribosomes make proteins for export
-Free ribosomes make proteins for intracellular use

Golgi apparatus

stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum
Final products are packeged in vesicles which can then be moves to the cell membrane for export
-Some of these vesicles remain in the cell as lysosomes and peroxisomes
-can also give rise to new membrane structures for the cells

Lysosomes

An organelle containing digestive enzymes
-Contain hydrolytic enzymes which digest particles or large molecules that enter them
-also responsible for digestion of uneeded or unhealthy cells and cell parts

Peroxisomes

Detoxify harmful substances that enter the cell
common in kidney and liver cells

Mitochondria

A powerhouse of the cell, organelle that is the site of ATP (energy) production
-double membranes organelle with fluid between the membrane
-Dots of enzymes attached to both membranes
-Enzymes catalyze oxidation reactions of cellular respiration and capture the energy of sugars in the bonds of ATP
-provide 95% of the cell's energy
-contain their own ribosomes and DNA you replicate themselves

Nucleus

Control center of the cel
-Contains the chromosomes on which the genes are located
-Find threads called chromatin in nondividing cells
-condense into visible chromosomes during cell division
-Nuclear membrane has two parallel membranes with nuclear pores pentatrating them
-Nuclear pores allows mRNA to leave the nucleus to go to the cytoplasm
-Also contains the nucleolus where ribosomal subunits are produced

Cytoskeleton

A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement
-support ER Mitochondria and free ribosomes

Microfiliments

Fine, threadlike proteins found in the cell's cytoskeleton
cellular muscles that provide for movement

intermidiate filaments

ropelike assemblies of fibrous polypeptides in the cytoskeleton that provide support and strength to cells

Microtubules

A hollow rod composed of tubulin proteins
maintain cell shape and move things within the cell

Centrosome

A structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center and is important during cell division. A centrosome has two centrioles.
-Coordinate building and breaking of microtubules in the cell
-centrioles are located within the centrosome
-during cell divsion makes the miotic spindel

Cell Extensions

surface extensions found in some cells

Microvilli

projections that increase the cell's surface area

Cilia

Hairlike projections that extend from the plasma membrane and are used for locomotion
short and numerous ;flagella are long

cell metabolism

sum of all chemical reactions that a cell carries out to maintain life

cell metabolism

The result of all the chemical reactions taking place in the cell cytoplasm.
mear;y a;; reactions are catalyzed by enzymes

Enzymes

Catalysts for chemical reactions in living things
-work best under certain conditions and can be denatured and made in effective by changing those conditions
-temp and PH

Catabolism

The sum total of all processes in an organism which break down chemicals to produce energy and simple chemical building blocks.

celluar respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

Glycolysis

the breakdown of glucose by enzymes, releasing energy and pyruvic acid.
-happens in cytoplasm
and form 2 net ATP
and molecules that enter the ,mitochondria
2atp

Citric Acid Cycle (Krebs Cycle)

A chemical cycle involving eight steps taht completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing acetyl CoA (derived from pyruvate) to carbon dioxide; occurs within the mitochondrion in eukaryotic cells and in the cytosol of prokaryotes; together with pyruvate oxidation, the second major stage in cellular respiration.
2atp

electron transport chain

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.
32/36 ATP

Anabolsim

the process whereby cells build molecules and store energy (in the form of covalent chemical bonds).
controlled by dna
-genes i DNA control production of proteins

Gene

A segment of DNA on a chromosome that codes for a specific trait
codon -sequencce of 3 bases partner with MRNA

Translation

Process by which mRNA is decoded and a protein is produced
-Mrna attaches to ribosomes

Transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA
base pairing rules assure that mRNA has correct sequence
-Peptide bonds join the amino acids to the growing polypeptide chain
tRNA molecules bring specific amino acids to the mRNA at the ribosomes -anticodon of tRNA base pairs with codon of mRNA which ensures that the correct amino acid is attached to the polypeptide

growth and reproduction of cells

fundemental charecteristics of life

Interphase

Normal condition of a cell

G1 phase

The first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins.
-growth
-normal functions
chromatin is single stranded

G2 phase

The second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

Mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes

Prophase

Chromosomes become visable, nuclear envelop dissolves, spindle forms

Metaphase

second phase of mitosis, during which the chromosomes line up across the center of the cell

Anaphase (Mitosis)

sister chromatids separate to poles

Telophase (mitosis)

chromosomes begin to uncoil, spindles break down, new nucleur membrane forms.

Cytokinesis

division of the cytoplasm into 2 cells

Plant Cell Cytokinesis

cell plate forms

Animal Cell Cytokinesis

cleavage furrow

internal regulators

proteins that regulate the growth of cells from the inside

external regulators

proteins that respond to events outside the cell; direct cells to speed up or slow down the cell cycle

metastasize

to spread by transferring a disease-causing agent from the site of the disease to other parts of the body

p53 mutation

causes cancer

Prophase 1 (crossing over)

Chromosomes become visible; nuclear envelope breaks down; crossing-over occurs.

synapsing

homologous chromosomes bonding closely together

Metaphase 1 image

homologs chromosomes line up along the center of the cell

Anaphase

homologs chromosomes separate and are pulled to opposite ends of the cell

Telophase 1 (meiosis)

A nuclear membrane forms around each cluster of chromosomes

Prophase (mitosis)

chromatin condenses into chromosomes
centriole pairs separate, move toward opposite sides of the cell, and form spindle fibers made of microtubules
the fibers radiate outward from the centrioles
nuclear membrane dissolves which allows spindle fibers to contact chromosomes

Metaphase (mitosis)

Chromosomes line up in the middle of the cell

anaphase 2, anaphase

sister chromatids separate and become daughter chromosomes

Telophase (mitosis)

chromosomes begin to uncoil, spindles break down, new nucleur membrane forms.

Cytokinesis

Division of the cytoplasm during cell division