Chapter 1 Flashcards
Give six characteristics of cells
homeostasis, reproduce, growth/repair, use energy, adapt, have a boundary/highly organized
What was Schleiden and Schwann’s contribution to the cell theory?
all organisms are made up of one or more cells, (( + the cell is the most basic unit of life))
What was Virchow’s contribution to the cell theory?
/cells are the structural units of life/ ((all cells arise only from preexisting cells)
What is the cell theory?
All cells arise from preexisting cells
What is the central dogma of molecular biology?
DNA-(transcription)->RNA-(translation)->Protein
Who invented the first microscope and what did he look at?
Hooke, looked at dead cells of cork
What sort of things could the first microscope see? What was its magnification?
Cells, nuclei, plant cell vacuoles, chloroplasts?
30x
Who invented the second microscope and what did he look at?
Van Leeuwenhoek, looked at live cells
What sort of things could the second microscope see? What was its magnification?
Everything Hooke could see plus mitochondria and bacteria 100x
Describe confocal microscopes
used to produce 3D images that are sharper than fluorescence microscopy
Give the two main reasons why cells are small. Include examples.
Large surface area to volume ratio (nutrient uptake, waste disposal, diffusion) and maintaining sufficient concentration of reactants and catalysts
Why can eukaryotic cells be larger than prokaryotic cells?
Their organelles allow them to concentrate molecules for reactions there
Compare prokaryotes and eukaryotes: nucleus, size, organelles, location and type of DNA, uni or multi cellular
Eukaryotes have a nucleus, are larger, have organelles, have linear DNA in nucleus, and are mostly multicellular
Prokaryotes have no nucleus, are smaller, do not have organelles, have circular DNA in their cytosol, and almost all are unicellular
Compare prokaryotes and eukaryotes: Shape, reproduction, ribosomes, speed of division, covering of DNA
Eukaryotes are variable in shape, reproduce slowly with mitosis, have 80s ribosomes, and have chromatin that packages their DNA
Prokaryotes are rod/sphere/corkscrew shaped, reproduce quickly with binary fission, have 70s ribosomes, and have “naked” DNA
Describe the endosymbiotic theory. Include the reasons why it would happen.
An ancestral early eukaryote engulfed an aerobic bacteria, creating a mitochondria. A cell like that engulfed a photosynthetic bacteria (a cyanobacteria), creating chloroplasts.
The aerobic bacteria would have handled the oxygen, and the anaerobic bacteria would ingest food and protect the aerobic “symbiote”.
What are the five main similarities between mitochondria, chloroplasts, and bacterial cells?
1 circular chromosome, binary fission replication, 70s ribosomes, small size, appearance on earth is anaerobic->photosynthetic->aerobic->eukaryotes
Explain how the presence of certain membranes supports the endosymbiotic theory
the inner lipid bylayer of mitochondira and chloroplasts would be the bacteral cell’s, and the outer layer came from the cell that engulfed it
Define cell
a small, membrane-enclosed unit filled with a concentrated aqueous solution of chemicals and endowed with the extraordinary ability to create copies of themselves by growing and then dividing in two
smallest living being, building blocks of life
Define nucleus
a large, circular organelle enclosed by a nuclear envelope that contains DNA
Define mitochondrion
worm-shaped branching organelles that generate energy (ATP) by cellular respiration in eukaryotic cells
Define chloroplast
large, green organelles that are found only in the cells of plants and algae and carry out photosynthesis
Define endoplasmic reticulum
an irregular maze of interconnected spaces enclosed by a membrane that makes most of the cell-membrane components and materials designed for export
Define golgi apparatus
stacks of flattened, membrane-enclosed sacs that modify and package molecules made in the ER that are destined to be secreted from the cell or transported to another compartment
`Define lysosome
small, irregularly shaped organelles in which intracellular digestion occurs, releasing nutrients from ingested food particles and breaking down molecules for recycling or excretion
Define peroxisome
small, membrane enclosed vesicles that provide a safe environment for a variety of reactions in which hydrogen peroxide is used to inactivate toxic moleucles
Define cytosol
a concentrated aqueous gel of large and small molecules; the part of the cytoplasm not contained in intracellular membranes
Define each of the three types of cytoskeletal filaments: Actin filaments, microtubules, and intermediate filaments
Actin filaments aid in muscle contraction
Microtubules help move chromosomes
Intermediate filaments strengthen the cell
What did Paul Nurse and colleagues discover?
certain cell division genes could be transferred between different species of yeast and even to humans
Define protozoans
free-living, nonphotosynthetic, single-celled, motile eukaryotes with elaborate anatomy.
What is the main advantage of multicellularity?
high specilization
Give some evidence for a common ancestor cell
Similarities in DNA/metabolic pathways/amino acids/proteins and the characteristics of mitochondria and chloroplasts
