Hesi review Biology questions
Why is polarity the most important characteristic of water?
The reults of the polarity are hydrogen bonding, a high specific heat value, and its versatile solvent properties
A cell from heart muscle would more than likely contain an unusually proportion of
Mitochondria
What part of cellular respiration produces the greatest amount of atp?
Electron transport chain
The Krebs and Calvin cycles both result in a net production of what?
ATP, NADH
Why is it important for cells to undergo mitosis?
Mitosis produces cells for growth and repair body tissue.
How is information transformed to make a protein?
DNA-RNA-protein
Hierarchic system of classification
Kingdom , Phylum, Class, order, family, Genus, Species
Allels
any of several forms of a gene , usually arising through mutation , that are responsible for heredity variation
Amino Acids
Any of a class of organic compounds that contain at least one amino group , -NH , and are carboxyl group, -COOH: The alpha amino acids , are building blocks from which proteins are constructed
Anaphase
Begins when chromosomes start to seperate.In this phase , the chromosome are considered seperate chromosomes.
Binary Fission
Fission into two organisms approxiamtley equal in size. Type of a sexual reproduction; parent cell splits into two identical daughter cells
Cellular Membrane
*Mosst important component of the cell, contributing to protection, communication, and the passage of substances into and out of the cell.
*Consists of a bilayer of phospholipids with proteins, cholesterol, and glycoproteins.
*Phospholipids are amphipathic molecules, this bilayer creates a hydrophobic region between the two layers of lipids, making it seletively permeable.
Chloroplasts
*Found in plants and are the sites of photosynthesis
*Produce cell energy
Chromosomes
Compact rod-shaped bodies located with in the nucleus of a cell; contain DNA
Codon
Three base sequence of messnger RNA ; each sequence of nucleotides in mRNA that base pairs with DNA base triplet.
* These code for a specific amino acid
Cytoplasm
Cellular contents betwenn the plasma membrane and the nucleus includes cytosol and organelles
Cytokinesis
division of the cytoplasm into two cells. It is achieved by the motor protein myosin pulling microfilaments of actin in the terminal web of the cytoskeleton . This creates a crease called the cleavage furrow around the equator of the cell, and eventually pinches into two
cytosol
fluid that surronds the organelles
Deoxyribonucleic Acid (DNA)
A unique molecule specific to a particular organism; it contains the genetic code that is necessary for replication.
*they described a double helical structure that contains the four nitrogenous babses adenine, thymine, guanine, and cytosine. Each base forms hydrogen bonds wiht another base of the complimentry strand. A-T, G-C.
Electron Transport Chain
Series of steps in cellular respiration that produces water and ATP. The energy harvest here is remarkable. for every glucose molecule, 28 to 32 ATP molecules can be produced.
Exocytosis
membrane enclose "secretory" vesicles form inside cell, fuse with plasma membrane, and release their contents into extracellular fliud
Endocytosis
materials move into a cell in a vesicle formed by plasma membrane
Glycolysis
Anaerobic breakdown of glucose; first step in cellular respiration. The conversion of glucose to pyruvate. This takes place in the cystol of the cell and produces 2 molecules of ATP, 2 molecules of pyruvate, and two molecules of NADH.
Lysosomes
Intracellular digestion. Packed with hydrolitic enzymes, lysososmes can hydrolyze proteins, fats, sugars, and nucleic acids.
Golgi Apparatus
Cell organelle that packages, processes, and distributes molecules from the er throughout the cell
Vacuoles
Membrane-enclosed structures, Plants have central vacuole that function as storage, waste disposal, protection, and hydrolysis.
Heterozygous
trait in an organism that contains different allels
Homozygous
Trait in an organism that contains identical allels
Hypotonic Solution
Has lower concentration of solutes than cytosol, so water enters cells faster than it leaves causing cells to swell and burst
Hypertonic Solution
Has higher concentration of solutes than cytosol, so water moves out of cells faster than it moves causing cells to shrink
Interphase
Stage of cell during which growth and DNA sysnthesis occur
Isotonic soluton
Concentration of solutes same on both sides of membrane, so water enters and exits at same rate and cells maintain normal shape and volume
Krebs cycle
Series of reactions that occur in the mitochondrion during cellular respiration. For a single consumed glucose molecule , 2 ATP molecules, six molecules of carbon dioxide, and six NADH molecules are produced.
Meiosos
* The special cell division that takes place in the gonads ( the ovaries and the testes) . In the process of meiosis, the chromosomes number is reduced from 46 to 23 , so when the egg and the sperm unite in fertilization the zygote will have the correct number of chromosomes
* Type of nuclear division that occurs as part of sexual reproduction; each daughter cell recieves the haploid number of chromosomes
Messenger RNA (mRNA)
Type of RNA formed from a template of DNA; this functions as a messenger form the original DNA helix in the nucleus to the ribosomes in the ctosol or on the rough ER. Here the ribosomes acts as the site of translation.
Metabolic pathway
Series of linked chemical reactions ; steps where reactions take place in a cell
*Progressing from a standpoint of high energy to low energy.
*All of the reactions are catalyzed by the use of enzymes.
Metaphase
All of the chromosomes align along the metaphase plate or the center of the cell.
Metaphase plate
Disk form during metaphase in which the chromosomes align in a quatorial plane of the cell
Mitosis
* The process in which the DNA is duplicated and distributed evenly to two daughter cells
* Type of cell division that produces two identical daughter cells; phases include prophase, prometaphase, metaphase, anaphase, and telophase.
Mitochondria
*Produce cell energy
*Found in most eukaryotic cells and are the site of cellular respiration
Organelles
Any of many cell "organs" or organized components
Phagocytosis
Process in which cells engulf food particles through the cell membrane
Phospholipids
Phosphate- containing fat molecule; forms the bilayer of a cell membrane. Consists of two fatty acids of vatying length bonded to a phosphate group . The phosphate group is charged and therefore polar.
Photosynthesis
Chemical process that converts light energy to synthesize carbohydrates. Consists of two seperate stages.
*The light reaction are those that convert solar energy to chemical energy. The cell accomplishes the production of ATP by absorbing light and using that energy to split a water molecule and transfer the electron, creating NADPH, and then producing ATP.These molecules are then used in the calvin cycle.
*The sugar produced is polymerized and stored as a polymer of glucose. These sugars are consumed by organism or by the plant itself to produce energy by cellular respiration
Plasma Membrane
Encloses and protects cell and contains functional protein such as enzymes that catalyze chemical reactions, receptors and bind ligands and regulate cellular activity , tansporters that regulate what enters and exits cell, and cell idenity markers
Prophase
The chromosomes are visibly seperate, and each duplicated chromosome has two noticable sister chromatids.
Prometaphase
The nuclear envelope begins to disappear, and the chromosomes begin to attach to the spindle that is formong along the axis of the cell
Ribosomes
*Organelles that read the RNA produced in the nucleus and translate the genetic instructions to produce proteins.
*Cells with a high rate of protein sysnthesis generally have large number of ribosomes.
* ribosomes are found in two locations, Bound are found in Er, and free are in the cytoplasm. The two are interchangeable and have identical structures.
Ribonucleic Acid (RNA)
Nucleic acid found in both nucleus and cytoplasm of cell; occurs in three forms: mRNA, ribosomal RNA , and tRNA. It is used in transfer and as a messenger in most species of the genetic code.
Rough ER
Section of endoplasmic reticulum that is covered with ribosoms; responsible for protein sysnthesis and membrane production
Smooth Er
Section of the endoplasmic reticulum that lacks ribosomes; functions in detoxification and metabolism of multiple molecules.
Steroids
Lipid that is a component of a cell membrane; many steroids are precursors to significant hormones.
Stop Codon
Sequence of bases that terminates translation during protein synthesis
Telophase
Chromosomes gather on eihter side of the now seperating cell.
Transcription
*An RNA strand complementary to the original strand of DNA is produced. The piece of genetic material produced is messenger RNA (mRNA)
*Process during protein synthesis in which the DNA molecule is used as a template to form mRNA. The RNA strand has nitrogenous bases, identical to those in in DNA with the exception of uracil, which is substituted for thymine.
Transfer RNA (tRNA)
RNA involved in protein sysnthesis; trnasfers a specific amino acid to the ribosomes and binds to mRNA
Water
* The most significant aspect of water is the polarity of its bonds. It is the polar nature of water that allows for hydrogen bonding between molecules.
*Water's high specific heat.This allows water to resist shifts in temperature.
*Hydrogen bonding also results in cohesive and adhesive properties. Cohesion id the ability of a molecule to stay bonded or attracted to another molecule of the same substance. Adhesion is the ability of water to bond or attract other molecules or substances.
*When water freezes it formsa a lattice , which causes the molecules to spread apart, resulting in the phenomenon of floating.
*Polarity of water also allows acts as a universal solvent . Water can be used to dissolve a number of different substances
Carbohydrates
are generally long chains, or polymers of sugars. They have many functions and serve many different purposes. The most important of these is storage , structure ,and energy.
Biological molecules
The most important molecules are
Carbohydrates
Lipids
proteins
nucleic acids
Lipids
Better known as fats , but specifically fatty acids, phospholipids, and steroids
Fatty Acids
Vary greatly, but simply are grouped into two categories , saturated and unsaturated
*Hydrocarbon tail of the faty acids is nonpolar. Which is important in the function of cellular membranes. The molecules combine in a way that creates a barrier that protects a cell.
Saturated Fats
*Contain no double bonds in their hydrocarbon tail
* solid
*Those that the general public consider detrimental ; cardiovascular problems are likely with diets that contain high quantaties of saturated fats
Unsaturated Fats
*One or more double bonds
*Liquid at room temperature
Proteins
*Most significant contributor to cellular function.
*Polymers of 20 molecules called amino acids
*Proteins are complex , consists of several structure types , and the largest of the biological molecules.
*Enzymes are particular types of proteins that act to catalyze different reactions or processes.
* Nearly all cellular function is catalyzed by some type of enzyme
Nucleic acids
Componets of the molecules of inheritance. DNA and RNA
Metabolism
The sum of all chemical reations that occur in an organism. In a cell, reactions take place in a series of steps called metabolic pathways.
Catabolism
Phase of metabolsim that involves breaking down complex chemical susbtances into smaller ones; = decompostion reactions
Anabolism
Phases of metabolism that involves building complex chemical substances from smaller , simpler ones; = sysnthesis reactions
Prokaryotic cells
lack a defined nucleus and do not contain membrane-bound organelles.
Eukaryotic Cells
Have a membrane-enclosed nucleus and a series of membrane-bound organelles that carry out the functions of the cell as directed by the nucleus.
*More complex of the two cell types
Cellular Reproduction
Cells reproduce by three different processes, all of which fall into two categories : sexual and asexual reproduction
Cellular Respiration
*Two Catabolic pathways that lead to cellular energy production. As a simple combustion reaction, cellular respiration produces far more energy than does its anaerobic counterpart, fermentation.
Sexual reproduction
the off spring originates from a single cell, yielding all cells produced to be identical.
* Two cells contribute genetic material to the daughter cells, resulting in greater vatriation.
In the hierarchic system of classification, what is the least inclusive.
Species
A molecule of water is bonded with another molecule of water by what type of bond?
Hydrogen
Selectively Permeable
Allows free passage of many lipid-soluble molecules but selectively controls crossing of ions or polar substances through transporter proteins
Passive transport
substances uses its own kinetic energy to move down concentration or electrochemical gradient across membrane until it reaches equilibrium (equal on both sides) does not require energy
Simple Diffusion
allows pasage of nonpolar substances
Facilitated Diffusion
allows pasage of larger and highly polar/ charged substances via transports proteins
Active Transport
Energy- requiring process in which transport proteins move solutes across membrane (up) its concetration gradient.
Ionic Bond
The force that binds a cation to an anion
Covalent Bond
Two atoms share electrons, generally in pairs, one from each atom.
Cell
The basic unit of life and the building block of tissues and organs.
Hydrogen Bond
a weak attraction between a slightly positive hydrogen atom on one molecule and a slightly negative oxygen or nitrogen atom on another molecule, or between such atoms on different parts of the same molecule; responsible for the cohesion of water and coiling of protein and DNA molecules, for example
How do phospholipds function in cells?
They are integral components of the plasma membrane
Proteins are polymers of what?
Amino acids
Which of the biological molecules are considered the most significant contributor to cellular function?
proteins
Lipids are better known as fats, but what are they specifically
Fatty acids, Phospholipids,steroids
Polysaccharide
ploymer of simple sugars; glycogen, starch, cellulose
Atom
the basic building block of a molecule that contains a nucleus and orbits
Monosaccharides
a simple sugar, or sugar monomer, chiefly glucose, fructose, and galactose.
What protein catalyze different reactions or processes?
Enzyme
Which of the biological molecules are componets of the molecules inheritance?
Nucleic acid
Aerobic
organism or cells that require oxygen to susutain life
Anaerobic
Organism or cell can function in low concentrations of oxygen (micro- aerobic) and some organisms exsist where no oxygen is present
Ionic Bond
Force of attraction that holds ions having opposite charges together
Isotope
Different kinds of the same atom that vary in weight: for a given element, the number of protons remains the same, while the number of neutrons varies to make different isotopes
Scientific Method Data
results generated by conducting experimental tests
Scientific Method Experiment
Implementation of scientific materials and methods designed to test a hypothesis ( should include a control group and experimental group)
Scientific Method Conclusion
Statements based on analysis of test results that discuss evidence to support or reject the hypothesis
Scientific Method Hyposthesis
Potential testable explanation for a phenomenon, based on observations and prior knowledge and experience
Scientific Method Observation
Use of senses to notice and study a phenomenon
Molecule
a group of stoms bonded together
Scientific Theory
Widely accepted concepts based on extensive experimental evidence
Element
one type of atom