A&P 1 exam 2

Differentiation

The specialization of cells based on gene expression

Stem Cells vs Progenitor Cells

Stem cells are unspecialized whereas progenitor cells are partially specialized

Totipotent vs Pluripotent

Totipotent cells can form every cell type as well as extra embryonic tissues. Pluripotent cells can form almost any cell type, but can’t form extra embryonic tissues.

Fluid Mosaic Model

A dynamic flexible barrier composed of a phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates.

Selective Permeability

Selective permeability is a property of cell membranes that only allows certain molecules to enter or exit the cell. Small, nonpolar, or hydrophobic molecules can easily slip through.

Receptors

Respond to extra cellular signals.

Pores, channels, and carriers

Transport small molecules and ions as well as transduce signals.

Enzymes

Catalyze chemical reactions.

Cellular Adhesion Molecules

Enable cells to stick to one another

Cell Surface Proteins

Act as the cells physical and functional boundaries

Integral Membrane Proteins

Go through part or all of the phospholipid bilayer and may extend from one or both sides. If it extends through both sides it is called a transmembrane protein.

Peripheral proteins

Attached to the internal or external surfaces and associate with one side of the bilayer rather than being embedded in it

Nucleus

Central in many cell types, contains the genetic material (DNA) which directs the cells functions

Ribosomes

Tiny spherical structures that are composed of protein and RNA, they provide structural support as well as enzymatic activity to link amino acids.

Endomembrane System

Group of membranes and organelles in eukaryotic cells that work together to modify package and transport, lipids and proteins.

Nuclear envelope, googly apparatus, endoplasmic reticulum, lysosomes, testicles, endosome, and plasma membrane are part of the system

Perioxsomes

Membrane bound, organelles that act as the cells metabolic and detoxification centers breakdown long fatty acid chains into useable molecules

Mitochondria

Inundated fluid filled sacks with the tendency to somewhat change size in shape they house most of the biochemical reactions that extract energy from the nutrient molecules in digested food.

Microfillaments

The thinnest cytoskeletal element, composed of actin protein, responsible for cell shape, whole cell locomotion, muscle contraction, and cytokinesis.

Intermediate filaments

Medium thickness rope like proteins they provide mechanical strength, anchor organelles and protect the cell from mechanical stress

Microtubules

Hollow tubes made of tubulin proteins. They maintain cell shape act as tracks for intercellular transport, form the miotic spindle, cilia and fagella.

Centrioles

Cylinder shaped that migrate to either side of the nucleus and produce spindle fibers that pull on or distribute chromosomes during cell division, they also produce cilia and fagella

Centrosome

Consist of a pair of central regulate cell motility, adhesion, and polarity and interphase, as well as facilitate The organization of the spindle apparatus during mitosis to ensure proper chromosome segregation

cilia

Hair like projections that are anchored to the cell by a basal body motel cilia beat in a coordinated or like motion to move fluids or mucus across the cell surface primary cilia act as cellular antennas to detect sensory signals

Fagella

Significantly longer than cilia and often occurred pairs their primarily used for cellular locomotion. They generate an undoing whip like motion that propels the entire cell through a fluid environment. Example is sperm cells.

Simple diffusion

The tendency of atoms, molecules and ions in a liquid or air to move from area of higher concentration to areas of lower concentrated chin as a result of their kinetic energy

Filtration

The movement of molecules through a membrane as a result of hydrostatic pressure

Facilitated diffusion

Diffusion in which of protein channel or carrier molecule transports the substance across the cell membrane from a region of higher concentration to a region of lower concentration

Active transport

A process that requires energy and a carrier molecule to move a substance across the cell membrane against the concentration gradient

Vesicular transport

A type of active transport that involves bringing contents into a cell or releasing contents out of a cell or the involvement of the two

Hypotonic solutions

Lower automatic pressure than the solution to which it is compared to water will diffuse into the cells, causing them to swell and sometimes burst

Isotonic solution

The exact same concentrations of solute as the inside of the cell, the cells get to remain the same

Hypertonic solutions

Have a greater osmotic pressure than which it is compared the cell shrink and or shrivel

Endocytosis

The process by which a cell membrane envelopes a particle and draws it into the cell in a vesicle

Exocytosis

The process of substances being transported out of a cell

Transcytosis

A combination of receptor mediated, endocytosis, and exocytosis that moves particles through a cell layer

Phagocytosis

ingests large solid materials such as cell debris, viruses, and bacteria

Cell eating

Pinocytosis

And Jess, extra cellular, fluids, nutrients, and dissolved substances

Receptor mediated endocytosis

A highly selective cellular process where the cells absorb specific extracellular molecules by binding them to specialized receptors on the cell surface

Mitosis

The process of nuclear division where a cells duplicated DNA is separated into two identical sets

Cytokinesis

The final physical cell division where the cytoplasm splits to create two distinct daughter cells

Interphase

A very active period between cell divisions when a cell metabolizes and prepares to divide. CELLS SPEND THE MOST TIME IN INTERPHASE.

Meiosis

Occurs only in cells that give a rise to sex cells meiosis halves the chromosome count 23

Prophase

The chromatin shorten and condense into chromosomes. Centrioles move to opposite sides of the cytoplasm, the nuclear envelope and nucleus dispurse. Mictrotubles assemble and associate with centrioles and the 2 sister chromatids that make each chromosome.

Metaphase

Chromosomes align preparing for separation. Spindle fibers from the centroles attatch to ythe centromeres of the sister chromatids of each chromosome. The chromosomes align midway between the centrioles.

Anaphase

Centromeres of chromatids separate and are now considered individual chromosomes. The centromeres separate and sister chromatids move apart with each new chromatid now an indvidual chromosome. Spindle fibers shorten and pul lthese chromosomes towards the centrioles.

Telophase

The newly formed nuclei separate.Chomosomes elongate and form chromatin threads, the nuclear envelope forms around each mass of chromatin. Nucleoli form and the microtubles break down.

Mitosis VS Cytokinesis

Mitosis is the process of division where a cells duplicated DNA is sperated into 2 identical sets. Cytokinesis is the final physical cell division where the cytoplasm splits to create 2 distinct daughter cells.

How do telomere loss, the interactions between cyclins and cyclin-dependent kinases (CDKs), and external signals like hormones and growth factors work together to control cell division?

External signals kick-start division by activating cyclins and cylcin dependent kinases. Internally cumulative telomere loss acts as a finite counter halting dving when cells age & protect DNA integrity.

How do disruptions in cell cycle regulation lead to the uncontrolled growth and division characteristic of cancer?

Cancer is a disease of uncontrolled cell division driven by the breakdown of mechanisims that normally regulate the cell cycle.

Benign VS Malignant

Benign tumors remain in place like a bump and are NON-CANCEROUS. If it enlarges it will eventually interfere with the function of healthy tissue. Maliignant tumors are CANCEROUS. They are usually agressive and invasive.

Metastasis

The spread of cancer cells from the primary site.

Proto-onctogens

Normal genes tht regulate cell growth, division, and survival

Oncogenes

Genes that normally control the cell cylce but are oveerexpressed increasing cell division rates.

Tumor-supressor genes

Encode proteins that normally inhibit cell division, but cause cancer when mutant.

Apoptosis

Sculpts organs from tissues that naturally overgrow.

Necrosis

Necrosis is the premature and uncontrolled death of cells in living tissue. It happens when cells are injured by outside forces like infections, poisons, severe burns, or a lack of blood flow.

Metabolism

Metabolism is the collection of all chemical reactions that occur in the body.

Anabolic VS Catabolic

In anabolic pathways smaller molecules synthesize into larger molecules. In catabolic pathways larger particles breakdown into smaller molecules.

Dehydration Synthesis

Anabolic process that joins small molecules by releasing the equivilant of a water molecules.

Hydrolysis

A catabolic process that ezymatically adds parts of a water molecule to split a bond.

Enzymes

Proteins that catalyze a specific biochemical raction.

What are the roles and functions of enzymes within cells?

They can speed metabolic reactions by a factor of a million or more by lowering the activation energy to start these reactions. Enzymes temporarily bind to and bring together recting molecules so they are in best position for a chemical interaction to occur resulting in th efomration of a product. As soon as the enzyme has done its job it can function repeatedly as its not consumed by the reactions.

Cofactors VS coenzymes

Cofactors are small organic molecules or ions that must combine with an enzyme for activity. Coenzymes are small nonprotein organic molecules that are required for the activity of a particular enzyme.

How does substrate concentration, temeprature, and pH level affect enzyme function?

When substrate concentration exceeds a certain level it no longer accelerates the rate of the reaction. As temperature increases reaction rates rise until an optimal range is exceeded, then the rates drop. Every enzyme has an “optimum pH”. If the environment becomes to acidic or basic these charges change which disrupts the enzymes structure and prevents it from binding.

Metabolic Pathways

A series of enzymatically controlled chemical reactions.

Rate-Limiting Enzyme

Usually present in small amounts that control the rate of a metabolic pathway by regulating one of it’s steps.

end-product inbition

A cellular control mechanism where the final product of a metabollic pathway acts as an inhibitor to an enzyme involved earlier in that same pathway.

Energy

The capability to move something and thus do work.

First Law of Thermodynamics

Energy can’t be created nor destroyed but it can change forms.

Second law of thermodynamics

The entire enthalpy of an isolated system will always increase over time.

Enthalpy

A thermodynamic property that measures the total heat content of a system

How do living cells use ATP for energy, and how do they constantly recharge it to keep the body running?

The chemical energy released when bonds are broken is tied to he synthesis of ATP. When energy is required for a metabolic reaction, the chemical energy stored in 1 or both high energy bonds may be quickly released when the phosphate bond breaks. The enregy is then transferred to another molecule in a metabolic reaction. The restoration of ATP is the process of reattatching an inorganic phosphate group to ADP through cellular respiration.

Oxidation

The removal of electrons

Reduction

The additon of electrons

Redox Reactions

Remove glucose and transfer it to oxygen, releasing the energy required to synthesize ATP.

Glycolysis

The 6 cabon sugar glucose breaks down in te cytosol into 3 byruvic aicd molecules with the net gain of 2 ATP and the release of hydrogen atoms with high energy electrons. Can be aerobic or anarobic.

Citric Acid Cycle

Takes the 3 carbon pyruvic acids generated by glycolysis and enters the mitochondria seperately. Each loses a carbon (generating 1 CO2) and combines with a coenzyme 2 carbon acetyl coenzyme A. More H2 atoms with high energy electrons are released. Each acetyl COA combines with a 4 carbon oxaloacetic acid to form the 6 carbon citric acid, a seroes of rections removed 2 carbs, synthesizes on ATP, and releases more hydrogen atoms with high energy electrons for each citric acid.

Electron Transport Train

The high energy electrons from the hydrogen atoms still contain most of the chemical energy of the orginal glucose molecule. Special carrier moelcules bring the hydrogen atoms to a series of enzymes that transfer much of the remaining energy to more ATP molecules. The elctrons eventually combine iwh hydrogen protons and anoxygen atom to form water. The function of oxygen as the final electron acceptor is why the process is aerobic. This occurs in the inner mitochondrial membrane.

What are the 3 phases of glycolysis? What occurs in these phases?

Phase 1 is priming, in this phase 2 phosphate groups are added to a glucose molecule (1 at each end) in a step called phosphorylation. This step requires energy from 2 ATP which are used to “prime” the glucose so that it is activated for some of the energy-releasing actions that will happen. Phase 2 is cleavage, in this phase the 6 carbon glucose molecule is cleaved into 2 3 carbon molecules. Phase 3 is the oxidation and gormation of ATP and the release of hydrogen atoms. In this phase the hydrogen carrier NADH is formed, ATP is synthesized and 2 3-carbon pyruvic acid molecules result.

What is the net yeild of ATP from glycolysis?

2 ATP molecules per glucose molecule