. Flashcards
Prokaryotic cells versus eukaryotic cells
Prokaryotic cells are smaller, whereas eukaryotic cells are larger. Prokaryotic cells have no membrane bound organelles, whereas eukaryotic cells do have membrane bound organelles. Prokaryotic cells have DNA in their nucleoid, whereas eukaryotic cells have DNA in their nucleus. Prokaryotic cells have 70S ribosomes, whereas eukaryotic cells have 80S ribosomes. Prokaryotic cells divide by binary fission, whereas eukaryotic cells divide by binary fission, mitosis, or meiosis.
Light versus electron microscopes
Light microscopes can magnify images, whereas electron microscopes can magnify and resolve images. Light microscopes can view living cells, movement, and color, whereas electron microscopes can not view living cells, movement, or color. Light microscopes have a smaller FOV size (up to 1K/2K), whereas electron microscopes have a larger FOV size (up to 250K).
Endocytosis versus exocytosis
Endocytosis is the process of a cell membrane taking in a substance via engulfing. Exocytosis is the process of the plasma membrane fusing with vesicles to remove substances out of the cell.
Pinocytosis vs phagocytosis
Pinocytosis or “cell drinking” allows the cell to take in liquid substances through small vesicles. Phagocytosis or “cell eating” allows the cell to take in solid substances through large vesicles.
Characteristics of mitochondria and chloroplasts
Mitochondria and chloroplasts both evolved by endosymbiosis, contain their own DNA, synthesize their own proteins, and contain 70S ribosomes. However, mitochondria generate ATP during cellular respiration, whereas chloroplasts do not.
Louis Pasteur experiment
Louis Pasteur tested for spontaneous generation. He found that after applying heat to a broth filled flask with a long neck curved downward, bacteria would not grow. His experiment showed that microbes cannot arise from nonliving materials.
Passive transport versus active transport
Passive transport requires energy to move molecules along the concentration gradient. Active transport requires energy to move molecules against the concentration gradient.
Simple diffusion versus facilitated diffusion
Simple diffusion is the transport of molecules across the cell membrane without the use of membrane proteins. Facilitated diffusion is the transport of molecules across the cell membrane that requires the use of membrane proteins.
CDKs
CDKs refer to cyclin-dependent kinases. They are enzymes that modify protein substrates during the cell cycle progression.
Davson-Danielli model
The Davson-Danielli model described the cell membrane having 2 layers of globular proteins between a phospholipid bilayer.
Singer-Nicolson model
The Singer-Nicolson model suggested that proteins are individually embedded in the phospholipid bilayer instead of laying on both sides.
Cholesterol
Cholesterol is a steroid that controls membrane fluidity by restricting movement of phospholipids to other molecules to prevent solidification.
Osmosis
Osmosis is the movement of water molecules from a high to low concentration through the cell’s partially permeable membrane.
Ribosomes (& free versus bound)
Ribosomes are the site of protein synthesis. Free ribosomes synthesize proteins in mitochondria, chloroplasts, cytoplasm, and nucleus. Bound ribosomes synthesize proteins in ER, golgi, lysosomes, and plasma membrane.
Cohesion versus adhesion
Cohesion refers to the attraction of molecules of the same substance. Adhesion refers to the attraction of molecules of two different substances.
Insulin
Insulin is an anabolic hormone/protein that promotes carbon energy deposition in the body.
What is a PCR?
PCR refers to a polymerase chain reaction. It makes copies of a DNA molecule by repeatedly copying a specific stretch.
Urea & the theory of vitalism
Urea is an organic compound used to excrete nitrogen. It’s accidental creation proved the theory of vitalism. The theory of vitalism is that solely living things can synthesize organic compounds.
Transcription
Transcription is the process of a gene’s DNA sequence being copied to make an RNA molecule. INITIATION begins when RNA polymerase binds to the promoter, which signals the DNA to unwind and prepares it for mRNA synthesis. ELONGATION is when RNA polymerase is added to the template strand in 3’ to 5’ region. TERMINATION is when the transcribing RNA polymerase releases DNA template and the nascent RNA and disassembly begins.
Translation
Translation is the process of ribosomal subunits assembling on mRNA to attract tRNA molecules to ultimately create a protein. INITIATION is when the small and large ribosomal subunits bind to mRNA. Then, tRNA binds to the start codon of mRNA. ELONGATION is when the amino acid sequences are extended and the formation of the amino acid chain is created. TERMINATION is when a stop codon binds to the A-site and disassembly begins.
Sense versus anti-sense strand
The sense strand has the exact sequence of the DNA transcript. The antisense strand contains the complementary sequence of the DNA transcript.
DNA Replication
Helicase unwinds DNA into single strands allowing each strand to be copied. Gyrase unwinds the supercoil to prevent DNA from breaking. Single stranded binding proteins keep the DNA strands separated and stabilized. Primase adds RNA nucleotides/primers to the complementary base pairs. DNA Polymerase III sythesizes the leading strand of DNA and the okazaki fragments. DNA Polymerase I digests RNA primers and replaces them with DNA nucleotides. Ligase joins the okazaki fragments on the lagging strand to form a single strand of DNA.
Conservative DNA replication versus semi-conservative DNA replication
Conservative replication produces one set of chromosomes with one strand composed of “old” DNA and one strand composed of “new” DNA. Semi-conservative replication produces one set of chromosomes with each strand composted of “old” and “new” wrapped around each other.
DNA electrophoresis
DNA electrophoresis loads DNA, RNA, or protein molecule samples into wells which then begin to separate based on their size and electrical charge
