Biology Of Cell Flashcards
Describe the structure of nucleic acids including base pairing and covalent vs hydrogen bonds.
Each nucleic acid includes Sugar, phosphate, nitrogenous base, hydrogen bond
Compare and contrast DNA and RNA structure.
DNA: Made up of nucleotides, Uses Thymine, double-stranded, nucleus only
RNA: Made out of nucleotides, has 2 hydroxyl groups, uses uracil, single-stranded, nucleus and cytoplasm
Define the following terms: chromosome, histone, homologous chromosome, centromere, sister chromatid, telomeres, diploid, haploid, gene, genetic locus, allele and genome.
Chromosome: DNA associated with an array of different proteins into a complex structure
Histone: Proteins that compact DNA to fit into the cell
Homologous chromosome: Two versions of each chromosome
Centromere: Where the chromatids get stuck
Sister Chromatid: two identical copies of the same chromosome formed by DNA replication
Telomeres: Protect functional genes from worn-down damage
Diploid: two complete sets of chromosomes
Haploid: Gametes/Sex cells, contain unpair chromosomes
Gene: Specific stretch of DNA that codes for protein
genetic locus: Specific location on the chromosome
Allele: One copy for the opposite of the other
Genome: The complete complement of genetic material in an organism
Describe the basic process of DNA replication and how it leads to the creation of identical sister chromatids.
Parents molecules: strands are together and have 1 chromosome and 1 chromatid
Separation of Strands: the parent strands start to separate
Daughter cells: Makes a copy of each strand then gets paired with a new strand “one old and one new”
Outline the events of each stage (G1, S, G2, M) of the cell cycle. Indicate which stage the majority of cells are in, when chromosomes replicate (DNA replication), when chromosomes segregate, and when the cell divides.
G1: Active gene expression, Preps DNA synthesis
S: DNA synthesis, creates identical sisters for each chromosome
G2: Prep for Cell Division
M: Cell division
Describe what main action happens in each of the following stages of mitosis: Prophase (3 actions), Metaphase, Anaphase and Telophase (3 actions).
Prophase: Dissolves nuclear membrane, co-dense DNA, Mitotic spindle forms
Metaphase: Nuclear membrane reforms, DNA unwinds/deco-dense, Mitotic spindle breaks down
Anaphase/Telophase: Two daughters produce by mitosis
Explain the role of meiosis in the diploid life cycle, including the terms gametes, somatic cells, and germ cells.
Meiosis produces haploid gametes from diploid germ cells, which are used in sexual reproduction to form a new diploid organism. Somatic cells are diploid and undergo mitosis for growth and maintenance of the body.
Describe the primary similarities and differences between mitosis and meiosis.
Mitosis and meiosis are two types of cell division processes. Mitosis results in two identical daughter cells, while meiosis produces four genetically diverse daughter cells due to chromosome pairing and recombination. Mitosis involves one cell division, while meiosis involves two rounds of cell division. Mitosis is involved in growth, repair, and asexual reproduction, while meiosis is involved in sexual reproduction and creating genetically diverse offspring.
Define dominant and recessive phenotypes, and describe how each corresponds with homozygous and/or heterozygous genotypes.
Dominant traits are expressed if an organism inherits one or two copies of the gene responsible for the trait.
Recessive traits are only expressed if an organism inherits two copies of the gene responsible for the trait.
Homozygous dominant and heterozygous genotypes are usually associated with dominant traits, while homozygous recessive genotypes are associated with recessive traits.
Identify Huntington’s disease and familial hypercholesterolemia as prevalent autosomal dominant human disorders, and identify cystic fibrosis and sickle cell anemia as prevalent autosomal recessive disorders.
Huntington’s disease and familial hypercholesterolemia are autosomal dominant disorders
Cystic fibrosis and sickle cell anemia are autosomal recessive disorders.
Huntington’s disease affects brain function, familial hypercholesterolemia causes high cholesterol, cystic fibrosis affects the lungs and other organs, and sickle cell anemia causes blood disorders.
Define the terms gene expression, transcription, and translation.
Transcription: The process of using a DNA template to make mRNA
Translation: Process of making a polypeptide using mRNA template
Explain the basic steps of transcription (initiation, elongation, termination).
Initiation: mRNA and ribosome segments come together. tRNA carrying the first amino acid binds to the start codon
Elongation: Amino acids are carried by tRNA to the mRNA. They create a long polypeptide chain
Termination: The stop codon in mRNA is found by the release factor, a protein, and translation components come apart. This releases the polypeptide chain
Explain the basic steps of translation (initiation, elongation, termination).
Initiation: RNA polymerase binds to the promotor region of the gene
Elongation: RNA polymerase slides along the region of the gene that gets transcribed, matching RNA nucleotide to DNA template
Termination: RNA polymerase hits the terminator region of gene and detaches from DNA
Explain how the triplet code works. Be able to build an amino acid chain from an mRNA sequence, if given the codon chart.
The bases in mRNA are read in triplets, Start codon is AUG and stops at UAA, UAG, UGA
Explain how DNA mutations can arise and describe different types (point, insertion, deletion) of mutations.
Point: Change in a single nucleotide base pair
Insertion: Addition of one or more nucleotides
Deletion: Removal of one or more nucleotide
Recognize the role of ATP as the universal energy molecule and that energy is stored in the phosphate bonds of ATP.
Explain biological oxidation and reduction in terms of electron and hydrogen/proton transfer, and the role electron carriers play in this process. Be able to identify specific examples of electron carriers used in glucose metabolism.
Oxidation: removal of electrons
Reduction: Addition of electrons
Electron carriers are molecules that accept and donate electrons to shuttle them from one molecule to another
EX: NAD+ = NADH
FAD = FADH2
Describe the fate of electrons, original and final carbon molecules, electron carriers, and ATP yield (per glucose molecule) for each of the 5 stages of glucose metabolism including glycolysis, pyruvate oxidation, the TCA cycle, electron transport chain and ATP synthesis.
Glycolysis: Broken down into pyruvate with production of two ATP molecules
Pyruvate oxidation: pyruvate is converted into acetyl- CoA and no ATP is produced
TCA cycle: acetyl-CoA is broken down into CO2 with two ATP production
Electron Transport: Electrons are transferred from electron carriers to electron transport chain and a proton gradient is created
ATP Synthesis: Production of ATP using the energy from the proton gradient created in the electron transport chain
Identify the cellular location of each of the 5 stages of glucose metabolism.
Glycolysis: occurs in cytoplasm
Pyruvate: occurs in mitochondria
TCA cycle: occurs in mitochondria
Electron transport: Occurs in inner mitochondrial membrane
ATP Synthesis: occurs in inner mitochondrial membrane
Summarize glycolysis in terms of original and final carbon molecules, and net ATP and NADH production.
Glycolysis is the first stage of glucose metabolism. It breaks down glucose into two molecules of pyruvate, producing a net of two ATP molecules per glucose molecule and two molecules of NADH. The original carbon molecules from glucose are converted into pyruvate, a three-carbon molecule. Glycolysis is a key process in energy production.
Explain what fermentation is, why fermentation is not ideal but aerobic respiration is for many cells, and identify the role of oxygen in this process. Provide examples of cell types that utilize fermentation versus aerobic respiration.
Fermentation is an anaerobic process that allows cells to produce energy in the absence of oxygen. However, it is not ideal for many cells because it produces only a small amount of ATP and wastes products that can be toxic to cells. In contrast, aerobic respiration produces much more ATP through the TCA cycle and electron transport chain and requires oxygen as the final electron acceptor. Examples of cells that use fermentation include bacteria, yeast, and muscle cells during intense exercise.
Explain the general function of the electron transport chain.
The electron transport chain transfers electrons from electron carriers to a series of proteins in the inner mitochondrial membrane. This creates a proton gradient that drives ATP synthesis through oxidative phosphorylation. The regulation of this process is crucial for cellular metabolism and function.
Generally describe how ATP synthase works.
ATP synthase is a protein complex in the inner mitochondrial membrane that uses the energy from a proton gradient to synthesize ATP from ADP and inorganic phosphate. It works by causing conformational changes in the protein complex, which drive the rotation of a central rotor and the synthesis of ATP. ATP synthase is highly efficient and regulated by the proton gradient created by the electron transport chain and oxidative phosphorylation.
What is Prophase
Centrioles have moved apart and the nuclear membrane starts to disappear
What is Prometaphase
Centrioles are at opposing ends and the nuclear membrane is nearly gone
What is Metaphase
Spindle fibers are attached to the chromosomes centromeres and they line up in the middle of the cell
DNA turns to mRNA by
Transcription
What us Anaphase
The centromeres split and move to apposite sides of the cell
If a heterozygous colorful chameleon was crossed with a homozygous-recessive colorful chameleon, what would be the genotype and phenotype of all potential offspring? What are the genotypes and phenotypes of the parents?
Bb, bb, Bb, bb
Parents (hetero: Bb, Homo: bb)
Offspring: 1/2 homo and 1/2 hetero
mRNA turn to protein by
Translation
What is Telophase
The cell membranes complete building, the nuclear membrane forms around chromosomes, and the cells form daughter cells
Scientists have discovered that there is a dominant trait (H) on the X chromosome (a sex-linked trait) that tells us someone will have long hair. Ben (a biological male) has always been able to grow super long hair, however, his wife Anna (a biological female) has always had super short hair. What are the possible genotypes and phenotypes of their offspring? What are the genotypes of Ben and Anna?
XHXh, XhY, XHXh, XhY
Ben: x^h y (long hair, must have “H” trait)
Anna: x^h x^h (short hair, cannot have “H” trait)
All their daughters will have long hair (x^ H, x^h), all their sons will have short hair (x^h y)
True or False: Point mutations are when there is any change or mutation in the DNA.
True
TRUE OR FALSE: Silent mutations have the same base and code for the correct amino acid.
False
describe the triplet code?
mRNA or a chain of base pairs is read. Each three is the instruction for an amino acid. These 3 bases are identified as codons, one codon is one amino acid. Multiple amino acids make proteins(translation)
TRUE OR FALSE: During deletion, base pairs are added.
False
TRUE OR FALSE: During insertion, base pairs are deleted.
False
