Semester 1 Final Exam Flashcards
Carbohydrates
sugar molecules. Along with proteins and fats, carbohydrates are one of three main nutrients found in foods and drinks.
Protein
large biomolecules and macromolecules that comprise one or more long chains of amino acid residues.
Lipids
a broad group of organic compounds which include fats, waxes, sterols, fat-soluble vitamins, monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include storing energy, signaling, and acting as structural components of cell membranes.
Nucleic Acids
large biomolecules that are crucial in all cells and viruses. They are composed of nucleotides, which are the monomer components: a 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nucleic acids are deoxyribonucleic acid and ribonucleic acid.
nucleus
stores genetic information
mitochondria
produces energy as ATP
endoplasmic reticulum
protein synthesis and lipid metabolism
Golgi apparatus
Modifies, sorts, and packages proteins into vesicles for transport within the cell
ribosomes
packages and sorts proteins
Lysosomes
Membrane-bound organelles containing enzymes that break down waste products and cellular debris
Vacuoles
Large sacs used for storage of water, nutrients, and waste products, particularly prominent in plant cells
Semipermeable plasma membrane
a type of synthetic or biologic, polymeric membrane that allows certain molecules or ions to pass through it by osmosis.
Polar head vs nonpolar tail
The heads (the phospho part) are polar while the tails (the lipid part) are non-polar. The heads, which form the outer and inner linings, are “hydrophilic” (water loving) while the tails that face the interior of the cell membrane are “hydrophobic” (water fearing).
Integral and Peripheral Proteins
Integral proteins are permanently embedded within the cell membrane, whereas peripheral membrane proteins are attached to the surface of the membrane at different times.
What can pass through the plasma membrane easily?
Small, nonpolar molecules like oxygen (O2), carbon dioxide (CO2), and hydrophobic molecules
Osmosis
the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential (region of higher solute concentration), in the direction that tends to equalize the solute concentrations on the two sides. It may also be used to describe a physical process in which any solvent moves across a selectively permeable membrane (permeable to the solvent, but not the solute) separating two solutions of different concentrations.
Tonicity
a measure of the effective osmotic pressure gradient; the water potential of two solutions separated by a partially-permeable cell membrane. Tonicity depends on the relative concentration of selective membrane-impermeable solutes across a cell membrane which determine the direction and extent of osmotic flux. It is commonly used when describing the swelling-versus-shrinking response of cells immersed in an external solution.
Isotonic
when water is leaving and entering the cell at the same rate. #balance
hypertonic
when water leaves the cell at a higher rate than it enters, so the cell shrivels and dies.
hypotonic
when water enters the cell at a higher rate than it enters, so the cell explodes.
diffusion
the tendency for particles of any substance to spread out into the available space
simple/passive transport
There is no energy at all, small molecules (O2,CO2), and no protein. There is a high-to-low concentration gradient.
facilitated diffusion
no energy, charged ions, particles are transported with help from a protein, high to low concentration
active transport
uses ATP, low to high concentration gradient, uses protein to assist transport
cellular respiration: what is it and what are we making?
a biological process where cells break down glucose (sugar) in the presence of oxygen to produce energy in the form of ATP (adenosine triphosphate), along with carbon dioxide and water as byproducts; essentially, cells are “making” usable energy (ATP) through this process.
glycolysis
the first stage of cellular respiration, where a glucose molecule is broken down into two pyruvate molecules, generating a small amount of ATP energy without the need for oxygen
krebs cycle
a series of chemical reactions that occur within the mitochondria during cellular respiration, where acetyl-CoA (a two-carbon molecule) is completely oxidized to produce carbon dioxide, energy carriers like NADH and FADH2, and a small amount of ATP, essentially serving as the second major stage of aerobic respiration after glycolysis; it requires oxygen to function properly.
electron transport chain
a series of protein complexes embedded in the inner mitochondrial membrane that transfer electrons from donor molecules like NADH and FADH2 to oxygen, releasing energy along the way which is used to pump protons across the membrane, creating a gradient that ultimately drives the synthesis of ATP through a process called oxidative phosphorylation; it is the final stage of aerobic respiration where most ATP is generated.
photosynthesis
the process by which plants, algae, and some bacteria use sunlight to convert carbon dioxide and water into glucose (sugar), releasing oxygen as a byproduct, essentially transforming light energy into chemical energy that can be stored as food for the organism
light dependant reaction
the initial stage where light energy from the sun is captured by chlorophyll molecules within chloroplasts and converted into chemical energy, specifically in the form of ATP and NADPH, which are then used in the subsequent “dark reaction” (Calvin cycle) to produce glucose
calvin cycle
a series of chemical reactions within photosynthesis that uses energy from the light-dependent reactions to convert carbon dioxide into glucose, essentially “fixing” carbon from the atmosphere into a usable sugar for the plant, and is often referred to as the “dark reactions” because it doesn’t directly require light energy; instead, it uses ATP and NADPH produced in the light reactions to drive the process
reactants v. products
the reactants are carbon dioxide and water, while the products are glucose (sugar) and oxygen; meaning that carbon dioxide and water are used by plants to produce glucose and release oxygen with the help of sunlight energy
mitosis
a process in biology where a single cell divides into two genetically identical daughter cells
mitosis interphase
the stage in a cell cycle where a cell grows, replicates its DNA, and prepares for cell division
mitosis prophase
the first stage of mitosis, the process of cell division, during which the genetic material (chromatin) condenses into visible chromosomes, and the mitotic spindle begins to form, preparing the cell for the separation of sister chromatids
mitosis metaphase
the stage during cell division (mitosis) where all the replicated chromosomes line up precisely in the middle of the cell, forming an imaginary plane called the metaphase plate, before they are pulled apart to separate into two daughter cells; it’s essentially the point where the chromosomes are most visible and aligned for equal distribution between the new cells
mitosis anaphase
the stage during the cell division process of mitosis where the replicated chromosomes (sister chromatids) separate at the centromere and are pulled apart by the spindle fibers, moving towards opposite poles of the cell, ensuring each new daughter cell receives a complete set of chromosomes
mitosis telophase
the final stage of mitosis, where the replicated chromosomes reach opposite poles of the cell, a new nuclear membrane forms around each set of chromosomes, and the chromosomes begin to decondense, essentially reversing the changes that occurred during prophase, ultimately preparing the cell to divide into two separate daughter cells through cytokinesis
products of mitosis
two genetically identical daughter cells produced from a single parent cell through the process of cell division
meiosis
a specialized type of cell division that occurs in sexually reproducing organisms, where a single cell divides twice to produce four daughter cells, each with half the number of chromosomes as the parent cell, resulting in the formation of gametes like sperm and egg cells crucial for sexual reproduction
meiosis 1
Prophase I:
This is the longest phase where homologous chromosomes pair up, condense, and undergo crossing over, exchanging genetic material.
Metaphase I:
Homologous chromosome pairs line up along the equator of the cell, attached to spindle fibers.
Anaphase I:
Microtubules pull the homologous chromosomes apart, separating them towards opposite poles of the cell.
Telophase I:
Nuclear membranes form around the separated chromosomes, and the cell undergoes cytokinesis, dividing the cytoplasm into two daughter cells, each with a haploid set of chromosomes.
meiosis 2
Prophase II:
Chromosomes condense further, and the nuclear membrane breaks down if necessary, preparing for the separation of sister chromatids.
Metaphase II:
The condensed chromosomes line up along the equator of the cell, attaching to spindle fibers.
Anaphase II:
The sister chromatids are pulled apart at the centromere and move to opposite poles of the cell.
Telophase II:
Nuclear membranes reform around the separated chromatids, and the cell undergoes cytokinesis, dividing into four haploid daughter cells.
products of meiosis
four haploid cells which are genetically unique from the parent cell, typically referred to as gametes (sperm or egg cells) in animals
heredity
the process by which traits or characteristics are passed from parents to their offspring through genes, essentially explaining why offspring resemble their parents to a certain degree; it’s also known as inheritance or biological inheritance.
monohybrid
AA, Aa, or aa. Monohybrid cross is crossing 2 traits of this format on a 2x2 punnet square.
dihybrid
Ex: AAAa, AaAa, AaAA, etc.
blood typing
A, B, AB, O
chi square
a statistical test used to compare observed data (experimental results) with expected data, determining whether any significant differences between them are likely due to chance or a real biological phenomenon
pedigrees
a genetic representation of a family tree that diagrams the inheritance of a trait or disease though several generations.
P, F1, and F2
“P” refers to the parental generation, “F1” represents the first filial generation (offspring of the P generation), and “F2” represents the second filial generation (offspring resulting from breeding individuals from the F1 generation)
chromatin
The spaghetti form of DNA
a complex structure made up of DNA tightly wound around protein complexes called histones, essentially packaging the genetic material into a compact form that allows it to fit inside the nucleus of a cell; it is the basic building block of chromosomes
chromatid
one of the two identical halves of a duplicated chromosome, meaning it’s a single strand of DNA that is part of a replicated chromosome, joined to its sister chromatid at the centromere, which separates during cell division to form two separate chromosomes in daughter cells; essentially, a chromatid is considered “half” of a chromosome after DNA replication occurs.
chromosome
a thread-like structure located inside the nucleus of a cell, composed of DNA tightly coiled around proteins called histones, which carries genetic information from cell to cell and is passed from parents to offspring, essentially containing the instructions that make each organism unique; humans typically have 23 pairs of chromosomes in each cell, making a total of 46 chromosomes.
centromere
a specialized region on a chromosome where sister chromatids are attached to each other
homologous chromosome
a pair of chromosomes that are the same size and shape, carry the same genes in the same order, and are inherited from different parents. A cell would have two copies of chromosome 1 for example; one from the mother and one from the father.
gene
the basic unit of heredity, a specific sequence of DNA that contains instructions for making a protein, which ultimately determines a particular trait or characteristic in an organism, like eye color or hair texture; essentially, genes are passed from parents to offspring and are located on chromosomes within the cell nucleus
trait
a specific characteristic of an organism
allele
one of the alternative forms of a gene that exists at a specific location on a chromosome, meaning it’s a variant version of a gene, with individuals inheriting one allele from each parent at a given genetic locus; these variations can lead to different traits within a population
inheritance
the process of passing genetic information from parents to their offspring
probability
the likelihood or chance that a specific event will occur, often used in genetics to predict the inheritance of traits based on the random assortment of alleles during reproduction
transcription
the process of copying a segment of DNA into RNA. Some segments of DNA are transcribed into RNA molecules that can encode proteins, called messenger RNA. Other segments of DNA are transcribed into RNA molecules called non-coding RNAs
translation
the process in living cells in which proteins are produced using RNA molecules as templates. The generated protein is a sequence of amino acids. This sequence is determined by the sequence of nucleotides in the RNA. The nucleotides are considered three at a time.1q@a
DNA to mRNA to Protein
Transcription is the process where a gene’s DNA sequence is copied into a messenger RNA (mRNA) molecule, essentially creating a “transcript” of the genetic information, while translation takes that mRNA and uses its code to build a protein by linking together amino acids in a specific sequence
DNA»_space; ATGCATCGACTG
mRNA > UACGUAGCUGAC
Protein > Gly Stop Mel (that’s not right but yk)
Where does translation and transcription occur
transcription occurs in the nucleus of a cell, while translation occurs in the cytoplasm, specifically on ribosomes
Properties of DNA and RNA
Key properties of DNA:
Structure: Double-stranded helix, forming a stable ladder-like structure due to base pairing between complementary nucleotides (adenine with thymine, cytosine with guanine).
Sugar: Deoxyribose
Bases: Adenine (A), Thymine (T), Cytosine (C), Guanine (G)
Function: Primarily stores genetic information in living organisms, passed on from generation to generation.
Key properties of RNA:
Structure: Typically single-stranded, although some complex structures can form depending on the RNA type
Sugar: Ribose
Bases: Adenine (A), Uracil (U), Cytosine (C), Guanine (G)
Function: Plays a crucial role in protein synthesis, including carrying genetic information from DNA to ribosomes (messenger RNA), transferring amino acids to the growing polypeptide chain (transfer RNA), and forming part of the ribosome structure (ribosomal RNA).
Mutations
a change in the DNA sequence of an organism, essentially a modification to the genetic code which can occur due to errors during DNA replication or exposure to environmental factors, and can result in variations that may be harmful, beneficial, or neutral to the organism depending on the change made
Insertion
a type of genetic mutation where one or more nucleotide base pairs are added to a DNA sequence, essentially inserting extra genetic material into the existing DNA strand, which can potentially disrupt the function of a gene depending on the size and location of the added sequence.
Deletion
a type of genetic mutation where a section of DNA is missing from a chromosome, resulting in the loss of genetic information; this can range from a single nucleotide to a large portion of a chromosome, potentially impacting the function of the affected gene(s).
Substitution
a type of genetic mutation where one nucleotide base in a DNA sequence is replaced with another, essentially swapping one “chemical letter” for another at a specific position on the DNA strand; this can potentially alter the amino acid sequence of a protein depending on where the substitution occurs within a gene
Inversion
a chromosomal rearrangement where a segment of a chromosome breaks off and reattaches to the same chromosome, but in the reversed orientation, meaning the gene order within that segment is flipped upside down; essentially, the DNA sequence is rearranged without any loss of genetic information, just a change in the linear order of genes within the chromosome.
translocation
a chromosomal abnormality where a piece of one chromosome breaks off and attaches to a different chromosome, essentially rearranging genetic material between non-homologous chromosomes; this can result in altered gene expression and potentially lead to genetic disorders depending on the affected genes and the extent of the translocation.
duplication
a genetic mutation where a segment of DNA is copied, resulting in the presence of two or more identical copies of that DNA sequence within the genome, essentially creating extra copies of a gene or a chromosomal region; this can significantly impact gene expression and function, and is considered an important mechanism in evolution by providing raw material for genetic diversity and adaptation.
nonsense
a genetic alteration that results in a premature stop codon within a gene, causing the protein synthesis process to end early, leading to a truncated and usually nonfunctional protein product; essentially, it’s a mutation that introduces a “stop signal” too soon in the DNA sequence, prematurely terminating protein production.
missense
a type of genetic alteration where a single change in the DNA sequence leads to a different amino acid being incorporated into the resulting protein, potentially altering its function; essentially, a single base pair substitution in the DNA code results in a different amino acid being coded for at that position in the protein sequence
silent
a type of substitution, or point, mutation, wherein the change in the DNA sequence of the gene has no effect on the amino acid sequence
CRISPR
Clustered Regularly Interspaced Short Palindromic Repeats,” referring to a naturally occurring genetic system found in bacteria that acts as a defense mechanism against viruses, allowing scientists to precisely edit DNA by targeting specific sequences using a guide RNA and an enzyme like Cas9, essentially acting as molecular scissors to cut and modify DNA at desired locations; this technology has significant potential in genetic research and medicine to treat diseases caused by genetic mutations.
CRISPR targetting
Cas9 first recognizes and binds to a
three-nucleotide sequence called PAM, which occurs throughout the genome.
CRISPR binding
Once Cas9 binds to a PAM sequence, it unwinds the DNA. If the guide RNA matches the DNA sequence next to
the PAM, the guide RNA will bind to the complementary DNA strand. If not, the DNA will zip back together and Cas9 will keep binding to other PAM sequences until it finds the matching target DNA.
CRISPR cleaving
Once the guide RNA binds to the DNA, it activates the nuclease activity
(DNA-cutting ability) of the Cas9 enzyme. Cutting DNA is also called
“cleaving.” Cas9 always cleaves both strands of the DNA three
nucleotides upstream (toward the 5’ end) of the PAM sequence.
CRISPR DNA repair
After Cas9 cleaves the DNA, cellular enzymes will attempt to repair the break. CRISPR-Cas9 takes advantage of
these repair mechanisms to alter the target gene sequence.
