Biology HESI another one
Terms in this set (89)
Hierarchic Organizational System
Most Inclusive Category in the Hierarchic Organizational System
(First on the System)
Most Restrictive Category in the Hierarchic Organizational System
Species (lowest on the system)
The Scientific Method
New observations are made and/or previous data are studied
A statement or explanation of certain events or happenings
Repeatable procedure of gathering data to support or refute the hypothesis
The data and its significance are fully explained
All life occurs in a water based (or aqueous) environment.
covalently bonded to
1 oxygen atom
The most significant aspect of water
Its polarity of its bonds that allow for hydrogen bonding between molecules.
Waters type of inter molecular bonding has several benefits
1 waters high specific heat: 1 degree Celcius
Due to the extent of hydrogen bonding between water molecules, which allows water to resist shifts in temperature.
2. Ability of oceans or large bodies of water to stabilize climates
3. Strong Cohesive and adhesive properties: Ability of a molecule to stay bonded or attracted to another molecule of the same substance.
: Ability of water to bond to or attract other molecules or substances
: Ability of a molecule to stay bonded or attracted to another molecule of the same substance.
When water freezes
Forms a lattice crystal.
Causes the molecules to spread apart, resulting in the phenomenon of ice floating in water.
Polarity of Water
Allows it to act as a versatile solvent. Water can be used to dissolve a number of different substances.
Most Imporant Molecules
4 nucleic acids
Long chains, or polymers of sugars.
serves many different purposes and functions like:
4 Form the backbone of DNA and RNA
Fats, specifically fatty acids, phospholipids and steroids.
Separated into 2 groups
: contain no double bonds in their
Solid in room temperature
; one or more double bonds.
Liquid in room temperature
1 Consist of two fatty acids of varying length
bonded to a phosphate group.
2 Charged and therefore polar and soluble in
water, whereas the hydrocarbon tail of the fatty
acids is non-polar and non-soluble in water.
3 Important in the function of cellular membranes.
Creates a barrier that protects the cell.
A component of membranes, but more important, many are precursors to significant hormones and drugs.
1 Most significant contributor to cellular function.
2 They are polymers of 20 molecules called *amino
3 Complex, consist of several structure types and
are largest of the biologic molecules.
4 a polymer of amino acids
1 Particular types of proteins that act to catalyze
different reactions or processes.
2 Nearly all cellular function is catalyzed by some
type of enzyme.
Components of the molecules of inheritance.
Deoxyribonucleic Acid: a unique molecule specific o a particular organism and contains the code that is necessary for replication
Ribonucleic Acid: Used in transfer of information from DNA to protein level and as a messenger in most species of the genetic code.
The sum of all chemical reactions that occur in an organism
1 The reactions that take place in a cell
2 These series of steps are called Metabolic pathways, progressing from a standpoint of high energy to low energy. All of the reactions are catalyzed by the use of enzymes.
The fundamental unit of biology.
The 2 types of cells
Prokaryotic and Eukaryotic
Lack a defined nucleus and do not contain membrane bound organelles
Have a membrane enclosed nucleus and a series of membrane bound organelles that carry out the functions of the cell as directed by the genetic information contained in the nucleus.
Many components that makes up a cell
First of the organelles which contains the DNA of the cell in organized masses called
1 contain all of the genetic information for the
regeneration (repair and replication) of the cell,
as well as all instructions for the function of the
2 Every organism has a characteristic number of
chromosome specific to the particular species.
1 Organelles that read the RNA produced in the
the genetic instructions to
2 Cells with a high rate of protein synthesis
generally have a large number of ribosomes
3 Can be found in two locations:
Endoplasmic Reticulum (Ribosomes are
bound to this. Makes cells for the cell
Free floating in this substance
ER and Cytoplasm
are interchangeable and
have identical structures although they
have slightly different roles.
Endoplasmic Reticulum (ER)
A membranous organelle found attached to the nuclear membrane and consists of two continuous parts.
Membranous system is covered with
a- Responsible for protein synthesis and
Section that lacks Ribosomes
a- Functions in the detoxification and
metabolism of multiple molecules.
1 - The packaging, processing, and shipping
2- Transports proteins from the ER throughout the
1- Where Intracellular digestion occurs.
2- Packed with hydrolytic enzymes, the lysosomes
can hydrolyze proteins fats, sugars and nucleic
3-Normally contain an acidic environment
1-Membrane-enclosed structures that have various functions, depending on cell type.
uptake food through the cell membrane, creating a food vacuole.
3- Plant cells have a central vacuole that functions as storage, waste disposal, protection and hydrolysis.
Mitochondria and Chloroplasts
Produce cell energy
- found in most eukaryotic cells and are the site of cellular respiration
- found in plants and are the site of photosynthesis
1- Most important component of the cell,
contributing to protection, communication, and
the passage of substances into and out of the
2-The membrane itself consists of a bi-layer of
phospholipids with proteins, cholesterol, and
glycoproteins peppered throughout.
3- Because phospholipids are amphipathic
molecules, this bi-layer creates a hydrophobic
region between the two layers of lipids, making
it selectively permeable.
4- Many of the proteins, which pass completely
through the membrane, act as transport
highways for molecular movement into and out
of the cell.
1- There are //two// catabolic pathways that lead
to cellular energy production
2-Simple combustion reaction, cellular respiration
produces far more energy than does its
anaerobic counterpart, fermentation.
3-C6H12O6 (s) + 6 O2 (g) → 6 CO2 (g) + 6 H2O
4-^^^^this balanced equation is the simplified
chemistry behind respiration.
5-//2-For every glucose molecule consumed this conversion results in overall ATP production numbers of 32-36 ATP molecules//
ATP or Adenosine Triphosphate
Compound that is used as energy currency of the cell
NADH or Nicotinamide adenine dinucleotide
1- Compound that acts as a reducing agent and is a
vehicle of stored energy is reduced.
2-This molecule is used as a precursor to produce
greater amounts of ATP in the final steps of
Cellular Respiration Step 1
- Conversion of glucose to pyruvate in a
-Takes place in the //cytosol// of the cell
and produces //two molecules of ATP//,
two molecules of //Pyruvate// and two
molecules of //NADH//
Cellular Respiration Step 2
-The //pyruvate// is transported into a
mitochondrion and used in the first of a
series of reactions called the *citric acid
-Takes place in the //matrix// of the
//mitochondria//, and for a //single//
consumed //glucose molecule//, //two//
//ATP// molecules, //six// molecules of
//carbon dioxide//, and //six NADH//
molecules are produced.
Electron Transport Chain
1-For every glucose molecule, 28 to 32 ATP can be
Overall production ATP production in Cellular Respiration is
32-36 ATP molecules for every glucose molecule consumed
Where energy originates and the precursor to the glucose molecule is is produced in a process called //photosynthesis//
2- The chemical reaction is just the reverse of
6CO2 + 6H2O ------> C6H12O6 + 6O2
3-The only notable difference is the addition of
light energy only he reactant side of the
4-Just as glucose is used to produce energy, so too must energy be used to produce glucose
First Stage of of Photosynthesis
-//Light reactions// reaction of the
solar energy being converted into
-The cell accomplishes the production of
ATP by absorbing light and using that
energy to split a water molecule and
transfer the electron, thus
creating//NADPH// nicotinamide adenine
Second Stage of Photosynthesis
Molecules from stage one are then used in the
to produce sugar.
- The sugar produced is polymerized and
stored as a polymer of glucose. These
sugar are consumed by organisms or by the
plant itself to produce energy by //cellular
HESI Hint for
a-Photosynthesis and Cellular Respiration are
b-Cellular Respiration needs glucose and oxygen
produced by photosynthesis
c-Photosynthesis needs water, carbon dioxide and
ATP produced by Cellular Respiration
Cells reproduce by three different processes that fall into these two categories
Sexual and asexual reproduction
Types of Asexual Reproduction 2 types
The offspring originates from a single cell, yielding all cells produced to be identical.
involves bacterial cells.
1-chromosome binds to the plasma membrane, where it replicates
2-as the cell grows it pinches in two, producing two identical cells
process of cell division occurs in five stages before pinching in two in a process called
The second process of cell division
-The cell pinches in two, forming two separate
When the cell pinches in two after Mitosis occurs
-The chromosomes are visibly separate
-Each duplicated chromosome has two
noticeable sister chromatids
-The nuclear envelope begins to disappear
-The chromosomes begin to attach to the
that is forming along the axis of the cell
-Chromasomes align along what is called
or the center of the
-Begins when the chromosomes start to
-In this phase, the chromatids are
-Chromosomes gather on either side of the
now separating cell.
end of mitosis
//Two cells contribute genetic material, resulting in significantly greater variation.//
-These two cells fertilize each other randomly
making it virtually impossible for cells to be alike
-The process that determines how reproductive
cells divide in a sexually reproducing organism
Meiosis 2 stages
consists of four stages
After cytokinesis, meiosis two begins
Here all four stages, identical to those of mitosis, occur
-results in four daughter cells that contain half as
many chromosomes as the parent.
-Preceding these events is a period called
Differences in Meiosis and Mitosis
occurs in prophase I
-during this phase, nonsister chromatids of homologous chromosomes cross at numerous locations
-Small section of DNA are transferred between these chromosomes, resulting in increased genetic variation
-The remaining three phases are the same as those in mitosis, with the exception that the chromosome pairs separate, not the chromosomes themselves.
-At fertilization, the chromosome number of the zygote would be
and the gametes produced by such an individual would also have 92 chromosomes
-A zygote resulting from the fertilization of gametes containing 92 chromosomes would have a chromosome number of 184. The need to produce gametes by meiotic an not mitotic division soon becomes obvious.
Study of heredity
-Gregor Mendel discovered the basic principles of genetics.
- He was able to determine that the observable traits in peas were passed from one generation to the next.
Family tree that traces the occurrence of a certain trait though several generations.
For every trait expressed in a sexually reproducing organism, there are at least two alternative versions of a gene called //alleles//
-For simple traits, the versions can be one of two
//Dominant or recessive//
Alleles of the same type for a trait
Different types of Alleles for a trait
Used to predict a genotype
-can be used to cross any number of different traits simultaneously
Methods of genetic understanding
Genetic material of a cell and is the vehicle of inheritance.
Watson and Crick described the structure of DNA
DNA double helical structure
contains nitrogenous bases
-each base forms hydrogen bonds with another
-Because of this bonding, the strands can be
replicated, producing identical strands of DNA
-During replication , the strands are separated.
-Then with the help of several enzymes new
complementary strands to each of the two
original strands are created.
-Produces two new double stranded segments of
DNA identical to the original.
-each gene along a strand of DNA is a template for protein synthesis. This production begins with a process called
basic structural unit and building block for DNA
A nucleotide is composed of 3 parts
Obligatory Base Pairing
-formation of a dna double helix from two complementary single strands
The enzyme that carries out the obligatory base pairing
In this process, an RNA strand, complementary to the original strand of DNA, is produced
The piece of genetic material produced in Transcription.
-Functions as a messenger from the original DNA helix in the nucleus to the ribosomes in the cytosol or on the rough ER.
-Here the Ribosome acts as the site of Translation. The mRNA slides through the Ribosome.
Has nitrogenous bases identical to those in DNA with the exception of
, which is substituted for
Every group of three bases along the stretch of RNA is called a
Each of these codes have a specific amino acid
Located on a unit called
transfer RNA (tRNA
, which carries a specific amino acid.
-Binds to the ribosome when its codon is sliding through the ribosome
What ends the chain and releases it into the cytoplasm, and then the protein folds onto itself and forms its complete formation
stop codon list
Transfer RNA (tRNA)
Multiple tRNA molecules bind in order and are released by the Ribosome.
-Each amino acid is bonded together and released by preceding tRNA molecule, creating an elongated chain of amino acids.
-ending in a
After the amino acid chain is ended by a stop codon the chain is then
released into the cytoplasm and the protein folds in on itself and forms its complete formation
-The DNA in the nucleus dictates what is produced in
translation through transcription
, the DNA in the nucleus has control over everything taking place in the cell.
-The proteins that are produced will perform all the different cellular functions required for the cells survival.
accelerates a reaction by reducing the activation energy or the amount of energy necessary for a reaction to occur. The catalyst is not used up in the reaction and can be collected at completion of the reaction. Various substances can be catalysts. Common examples include metals and proteins (protein catalysts are called enzymes).
The cellular membrane is the most important component of the cell, contributing to protection, communication, and the passage of substances into and out of the cell. The cell membrane itself consists of a bilayer of phospholipids with proteins, cholesterol, and glycoproteins peppered throughout. Because phospholipids are amphipathic molecules, this bilayer creates a hydrophobic region between the two layers of lipids, making it selectively permeable. Many of the proteins, which pass completely through the membrane, act as transport highways for molecular movement into and out of the cell
YOU MIGHT ALSO LIKE...
HESI A2 Test Preparation | Mometrix Nursing Guide
HESI Admission Assessment Biology
Hesi A2 Biology
Chapter 4- Cellular Metabolism
OTHER SETS BY THIS CREATOR
Superficial muscles of mastication
Muscles of facial expressions
Muscles of the head
THIS SET IS OFTEN IN FOLDERS WITH...
Hesi A2 Math
HESI - Math
Histology ( tissues)