BIOLOGY Flashcards
There is a hierarchy system of organization. The system is most inclusive as kingdom and least as species. The order is as follows:
Kingdom Phylum Class Order Family Genus Species
When did Charles Darwin first introduce the notion of evolution and how? What did he propose?
In 1859, in his book “On the Origin of Species”. Charles Darwin proposed that current species arose from a process he called “descent with modification”.
Science is a process. For an experiment to be performed, the following steps must be taken:
- Hypothesis: a statement or explanation of certain events or happenings.
- Experiment: a repeatable procedure of gathering data to support or refute the hypothesis.
- Scientific Process: the conclusion.
What elements does a molecule of water (H2O) contain? What bond is involved?
2 hydrogen atoms covalently bonded to 1 oxygen atom.
What is the most significant aspect of water?
The polarity of its bonds.
What allows for hydrogen bonding between molecules?
The polar nature of water.
The type of intermolecular bonding in water has 4 resulting benefits. What are they?
- Specific Heat
- Strong cohesive and adhesive properties.
- Forming a lattice when frozen.
- The polarity of water, allowing it to act as a versatile solvent.
What is the specific heat of a molecule?
The amount of heat necessary to raise the temperature of 1 gram of that molecule by 1 degree Celsius.
Is the specific heat of water high or low? What does this allow water to do?
The specific heat of water is high. It allows water to resist shifts in temperature. One powerful benefit is the ability of oceans or large bodies of water to stabilize climates.
What is cohesion?
The ability of a molecule to stay bonded or attracted to another molecule of the same substance. Example: how water tends to run together on a newly waxed car.
What is Adhesion?
The ability of water to bound to or attract other molecules or substances. Example: when water is sprayed on a wall, some of it sticks to the wall.
What is a lattice in terms of the intermolecular bonding characteristics of water? What happens when a lattice is formed?
A lattice is formed when water freezes. This causes the molecules to spread apart, resulting in the phenomenon of floating.
Most molecules, when they are in the solid form, do not float on the liquid form of the substance. True or False?
True
What would happen if ice did not float?
Lakes would freeze from the bottom to the top. Life could not exist as we know it.
What are the most important molecules in Biology?
Carbohydrates
Lipids
Proteins
Nuclei acids
What are carbohydrates? What are its 3 most important functions?
Long chains or polymers of sugars. Its 3 functions are:
Storage
Structure
Energy
What are lipids?
Lipids or fats, but specifically fatty acids , phospholipids, and steroids.
What are the 2 major categories that fatty acids are grouped in?
Saturated and Unsaturated
What are Saturated fats?
- They contain no double bonds in their hydrocarbon tail.
- Solid
- Are considered detrimental by the general public because they may cause cardiovascular problems, which are likely with diets that contain high quantities of saturated fats.
What are Unsaturated fats?
- Have one or more double bonds.
2. Are liquid at room temperature.
What are phospholipids?
Consist of two fatty acids varying length bonded to a phosphate group. The phosphate group is charged and therefore polar, whereas the hydrocarbon tail of the fatty acids is non polar. This quality is particularly important in the function of cellular membranes. The molecules combine in a way that creates a barrier that protects the cell.
What are steroids?
The last of the lipids, they are a component of membranes, but more importantly many precursors to significant hormones.
What are the most significant contributors to cellular function?
Proteins
What are Proteins?
Proteins are polymers of 20 molecules called amino acids. Proteins are complex, consist of several structure types, and are the largest of the biological molecules.
What are Enzymes?
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.
What are Nucleic Acids?
Components of the molecules of inheritance.
What is the unique molecule specific to a particular organism and contains the code that is necessary for replication?
Deoxyribosenucleic Acid (DNA) (Add picture)
What nucleic acid is used in transfer and as a messenger in most species of he genetic code?
Ribonucleic Acid (RNA)
What is Metabolism?
The sum of all chemical reactions that occur in an organism.
In a cell, reactions take place in a series of steps called ____________, progressing from a standpoint of high energy to low energy.
Metabolic Pathways
What is the fundamental unit of biology?
The cell.
What are the two types of cells?
Prokaryotic and Eukaryotic
Cells consist of many components, most of which are referred to as ___________.
Organelles
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What is the difference between Prokaryotic Cells and Eukaryotic Cells?
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 call as directed by the nucleus. It is the most complex of the two cells.
What is the Nucleus of a cell?
The nucleus contains the DNA of a cell in organized masses called chromosomes.
_____________ contain all of the material for the regeneration of the cell, as well as all instructions for the function of the cell.
Chromosomes
Every organism has the same number of chromosomes. True or False?
False.
Every organism has a characteristic number of chromosomes specific to the particular species.
____________ are organelles that read the RNA produced in the nucleus and translate the genetic instructions to produce protein.
Ribosomes
Cells with a high rate of protein synthesis generally have a large number of ribosomes. True or False?
True
What two locations are ribosomes found in the cell?
Where can you find bound ribosomes?
Where can you find free ribosomes?
- Endoplasmic Reticulum (ER)
- bound ribosomes - Cytoplasm
- free ribosomes
These two types of ribosomes are interchangeable and have identical structure, although they have slightly different roles.
What is the Endoplasmic Reticulum?
A membranous organelle found attached to the nuclear membrane and consists of two continuous parts.
Through an electron microscope, it is clear that part of the membranous system is covered with ribosomes. This section of the ER is referred to as ____________, and it is responsible for _____________ and ___________.
Rough ER; protein synthesis; membrane production
The other section of the ER lacks ribosomes and is referred to as ____________. It functions as the ____________ and ___________ of multiple molecules.
Smooth ER; detoxification; metabolism
What is the Golgi Apparatus?
A packaging, processing, and shipping organelle. The Golgi apparatus transports materials from the ER throughout the cell.
In what organelle in the cell does intracellular digestion take place?
Lysosomes
What is the function of a Lysosome?
Packed with hydrolytic enzymes, the lysosomes can hydrolyze proteins, fats, sugars, and nucleic acids.
What are Vacuoles?
Are membrane-enclosed structures that have various functions, depending on cell type.
What process do many cells utilize in order to uptake food through the cell membrane, creating a food vacuole ?
Phagocytosis
What are the 4 functions of a plant’s central vacuole?
- Storage
- Waste disposal
- Protection
- Hydrolysis
What are the two distinct organelles in a cell that produce cell energy?
Mitochondrion and Chloroplast.
What is a Mitochondria?
They are found in most eukaryotic cells and are the site of cellular respiration.
What are Chloroplasts?
Found in plants and are the site of photosynthesis.
The _________ __________ is the most important component of the cell, contributing to protection,communication, and the passage of substances into and out of the cell.
Cellular Membrane
The cell membrane itself consists of a ____________ of ___________ with proteins, cholesterol, and glycoproteins peppered throughout.
Bilayer; Phospholipids
Why does the phospholipid bilayer of a cell membrane create a hydrophobic region between the two layers of lipids, making it selectively permeable?
Because the phospholipids are amphipathic molecules.
The definition of amphipathic: (of a molecule, especially a protein) having both hydrophilic and hydrophobic parts.
Many of the proteins, which pass __________ through the membrane, act as transport highways for molecular movement into and out of the cell.
Completely
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There are ______ catabolic pathways that lead to cellular energy production. As a simple combustion reaction,cellular respiration produces far more energy than does its anaerobic counterpart, ____________ .
Two; fermentation
What is the simplified chemistry behind respiration? This process occurs in a series of how many complex steps?
a. C6H12O6 + 6O2 —-> 6CO2 + 6H2O
b. three
What is the name of the molecule that represents the currency of the cell?
Adenosine Triphosphate (ATP)
Another compound that acts as a reducing agent and is a vehicle of stored energy is reduced ____________ ____________ ____________ .
Nicotinamide adenine dinucleotide (NADH)
What molecule is used as a precursor to produce greater amounts of ATP in the final steps of respiration?
NADH
What is the first step of cellular respiration, where glucose is converted to pyruvate?
The process of Glycolysis.
Where does glycolysis occur, and what are the products?
It takes place in the cytosol of the cell and produces 2 molecules of ATP, 2 molecules of pyruvate, and 2 molecules of NADH.
In step two of cellular respiration, pyruvate is transported into a mitochondrion and used in the first series of reactions called the __________ __________ .
Krebs Cycle
Where does the Krebs Cycle happen, and what are the products?
This cycle takes place in the matrix of the mitochondria. For a single consumed glucose molecule, 2 ATP molecules, 6 molecules of CO2, and 6 NADH molecules are produced.
What is the third step of cellular respiration?
The third step begins with the oxidation of the NADH molecules to produce oxygen and finally to produce water in a series of steps called the electron transport chain (ETC).
What are the products of the electron transport chain (ETC) ?
The energy harvested here is remarkable. For every glucose molecule, 28 to 32 ATP molecules can be produced.
This conversion results in overall ATO production numbers of 32 to 36 ATP molecules for every glucose molecule consumed.
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The precursor to the glucose molecule is produced in a process called _____________ .
Photosynthesis
What is the chemical reaction representing photosynthesis?
6CO2 + 6H2O +Light energy —-> C6H12O6 + 6O2
the reverse of cellular respiration
What is the major notable difference between cellular respiration and photosynthesis?
The addition of light energy on the reactant side of the equation.
Just as glucose is used to produce energy, so too must energy be used to _________ glucose.
Produce
What are the two different stages of Photosynthesis ?
- Light reactions
2. Calvin cycle
What are light reactions in photosynthesis ?
Light reactions are those that convert solar energy to chemical energy.
The cell accomplishes the production of ________ by absorbing light and using that energy to split a ________ molecule and transfer the electron, thus creating nicotinamide adenine dinucleotide phosphate (NADPH) and producing ATP.
ATP; water
NADPH molecules are used in what cycle to produce sugar?
Calvin Cycle
The sugar in the Calvin Cycle is _____________ and stored as a polymer of glucose. These sugars are consumed by ___________ or by the plant itself to produce energy by _____________ ____________ .
Polymerized; organisms; cellular respiration
Hesi Hint #1
When attempting to understand cell respiration and photosynthesis, keep in mind that these processes are cyclical. In other words, the raw materials for one process are the products of the other process. The raw materials for cell respiration are glucose and oxygen, whereas the products of cell respiration are water, carbon dioxide, and ATP. Plants and other autotrophs will utilize the products of cell respiration in the process of photosynthesis. The products of photosynthesis (oxygen, glucose) become the raw materials of cell respiration.
Cells reproduce by three different processes, all of which are asexual reproduction. True or False?
False.
Cells reproduce by three different processes, all of which fall into two categories: sexual and asexual reproduction.
What are the 2 types of asexual reproduction?
Binary Fission
Mitosis
Describe the process of binary fission.
In this process, the chromosome bonds to the plasma membrane , where it replicates. Then as the cell grows, it punches in two, producing two identical cells.
Describe the process of mitosis.
This process of cell division occurs in five stages before pinching in two in a process called cytokinesis. The five stages are prophase, prometaphase, metaphase, anaphase, and telophase.
What happens during Prophase ?
The chromosomes are visibly separate, and each duplicated chromosome has two noticeable sister chromatids.
What happens during prometaphase?
The nuclear envelope begins to disappear, and the chromosomes begin to attach to the spindle that is forming along the axis of the cell.
What happens during Metaphase?
Follows with all the chromosomes aligning along what is called the metaphase plate, or the center of the cell.
What happens during Anaphase?
Begins with chromosomes start to separate. In this phase, the chromatids are considered separate chromosomes.
What happens in Telophase?
Chromosomes gather on either side of the now separating cell. This is the end of mitosis.
What is the second process associated with cell division?
Cytokinesis
What happens during Cytokinesis?
During this phase, which is separate from the phases of mitosis, the cell punches in two, forming two separate identical cells.
What’s the difference between asexual and sexual reproduction?
I’m asexual reproduction, the offspring originates from a single cell, yielding all cells produced to be identical. In sexual reproduction, two cells contribute genetic material, resulting in significantly greater variation. These two cells find and fertilize each other randomly, making it virtually impossible for cells to be alike.
What process determines how reproductive cells divide in a sexually reproducing organism?
Meiosis
Meiosis consists of two distinct stages, ____________ and ____________, resulting in four daughter cells.
Meiosis I
Meiosis II
Each of these daughter cells (in meiosis) contains _________ as many chromosomes as the parent.
Half
What is the first stage of meiosis?
Interphase
What happens during Interphase?
The chromosomes are duplicated and the cell prepares for division.
Hesi Hint #2
Below:
What plant did Gregor Mendel use to discover the basic principles of genetics?
Garden peas; By careful experimentation, he was able to determine that the observable traits in peas were passed from one generation to the next.
What have scientists found from Mendel’s studies?
They have found that 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 types: ____________ or _____________.
Dominant
Recessive
If both of the alleles are the same type, the organism is said to be _____________ for that trait.
Homozygous
If both of the alleles are different types, the organism is said to be _____________ for that trait.
Heterozygous
Hesi Hint #3
If an allele is dominant for a particular trait, the letter chosen to represent that allele is capitalized. If the allele is recessive, then the letter is lowercased. If a dominant allele is present, then the phenotype expressed will be the dominant. The only way a recessive trait will be expressed is if both alleles are recessive.
What is the name of the device that is used to predict the possible genotype (the combination of alleles) and phenotype (what traits will be expressed) of the offspring of sexual reproduction?
Punnett square
Name 4 other methods of genetic expression.
Multiple alleles
Pleiotropy
Epistasis
Polygenic inheritance
What is a pedigree?
A pedigree is a dimly tree that traces the occurrence of a certain trait through several generations. A pedigree is useful in understanding the genetic past as well as the possible future.
In 1953, what two scientists described the structure of DNA?
Watson and Crick
What structure did Watson and Crick describe?
A double helix structure that contains the four nitrogenous bases; adenine, thymine, guanine, and cytosine.
What types of bonds are formed between each nitrogenous base and its complimentary strand ?
Hydrogen bonds
What occurs during DNA replication?
The strands of DNA are separated. Then, with the help of several enzymes, new complimentary strands to each of the two original strands are created. This 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
Protein synthesis begins with what process?
Transcription
What happens during the process of transcription?
An RNA strand , complementary to the original strand of DNA, is produced. The piece of genetic material produced is called messenger RNA (mRNA). The RNA strand has nitrogenous bases identical to those in DNA with the exception of uracil , which is substituted for thymine.
What is the main function of mRNA?
It functions as a messenger from the original DNA helix in the nucleus to the ribosomes in the cytosol or on the rough ER. Hers, the ribosome acts as the site of translation. The mRNA slides through the ribosome.
What is the name for every group of three bases along the stretch of RNA?
What does each codon code for?
A codon; a specific amino acid.
Where is the anticodon located?
It is literally located on a unit called transfer RNA (tRNA), which carries a specific amino acid. It binds to the ribosome when its codon is sliding through the ribosome.
Remember that a protein is a polymer of amino acids, and multiple tENA molecules bind in order and are released by the ribosome.
Each amino acid is bonded together and released by the preceding _________ __________, creating an elongated chain of _________ _________.
tRNA molecule; amino acids
What ends the amino acid chain in transcription?
Stop codon
Where is the amino acid chain chain released to after ending at the stop codon during transcription?
Cytoplasm; the protein folds into itself and forms its complete conformation. Next we have translation. 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’s survival.
What is the first stage of protein synthesis?
Transcription, a process in which a messenger RNA (mRNA) molecule forms along one gene sequence of a DNA molecule within the cell’s nucleus. As It is formed, the mRNA molecule separate from the DNA molecule, is edited, and leaves the nucleus to the large nuclear pores. Outside the nucleus, ribosome subunits attach to the beginning of the mRNA molecule and begin the process of translation.
What is the second stage of protein synthesis?
Translation, transfer RNA (tRNA) molecules bring specific amino acids-encoded by each mRNA codon- into place at the ribosome site. As the amino acids are brought into the proper sequence m, they are joined together by peptide bonds to form long strands called polypeptides. Several polypeptide chains may be needed to make a complete protein molecule.
What is the main function of mRNA?
It functions as a messenger from the original DNA helix in the nucleus to the ribosomes in the cytosol or on the rough ER. Hers, the ribosome acts as the site of translation. The mRNA slides through the ribosome.
What is the name for every group of three bases along the stretch of RNA?
What does each codon code for?
A codon; a specific amino acid.
Where is the anticodon located?
It is literally located on a unit called transfer RNA (tRNA), which carries a specific amino acid. It binds to the ribosome when its codon is sliding through the ribosome.
Remember that a protein is a polymer of amino acids, and multiple tENA molecules bind in order and are released by the ribosome.
Each amino acid is bonded together and released by the preceding _________ __________, creating an elongated chain of _________ _________.
tRNA molecule; amino acids
