Biology 333 Homework 1 Flashcards

Flashcards covering the foundational concepts of cell biology, microscopy levels, organelle functions, and common model organisms used in biological research.

Cell

The smallest living unit, capable of diverse sizes, shapes, and behaviors.

Amino acid

The twenty different building blocks used to create proteins with different sequences, conformations, and functions.

Mutation

A change in the DNA sequence that can result from errors during DNA replication and serves as the basis for evolution when combined with selection.

Evolution

The process of mutation and selection over the course of many generations.

Central Dogma of molecular biology

The flow of genetic information involving the correct series of biochemical reactions: DNA $\rightarrow$ transcription $\rightarrow$ RNA $\rightarrow$ translation $\rightarrow$ protein.

Genome

The entire sequence of nucleotides that make up a cell's DNA.

Micrometer ($\text{μm}$)

The unit of length generally used to measure a typical plant or animal cell.

Resolution limit of the unaided eye

The smallest distance two points can be separated and still resolved without a microscope, which is equal to $200 \text{μm}$.

Surface area to volume ratio

A major factor that limits cell size because high ratios are needed to support the cell's metabolic requirements.

Resolution

The measure of the clarity of an image or the minimum distance where two points remain distinguishable.

Light microscopy resolution

Limited by the wavelength of light, this type of microscopy can resolve two points separated by as little as $0.2 \text{μm}$.

Electron microscopy

A technique that can resolve images down to nearly $1 \text{nm}$ because electrons have a much shorter wavelength than photons.

Prokaryotic domains

The two different domains that classify prokaryotes: Bacteria and Archaea.

Plasma membrane

A cellular structure that is common to all three domains of life (Bacteria, Archaea, and Eukarya).

Nucleus

Determining feature of eukaryotic cells that is absent in prokaryotic cells; it confines the DNA behind a double membrane.

Eukaryotic size scale

On average, these cells are $10$ times longer and have $1000$ times more volume than prokaryotic cells.

Nuclear envelope

A structure made of two concentric membranes that is continuous with the membrane of the endoplasmic reticulum.

Mitochondria

Organelles with inner and outer membranes that perform cellular respiration by using oxygen and sugar to produce $\text{ATP}$.

Thylakoids

The third, innermost membrane within chloroplasts where chlorophyll is located.

Photosynthesis

The process where plants incorporate carbon from $\text{CO}_2$ into high-energy sugar molecules using energy captured from sunlight.

Endosymbionts

A description for mitochondria and chloroplasts because they contain their own genome and divide independently, but cannot function for long when isolated from the cell.

Exocytosis

The process by which eukaryotic cells trigger the release of molecules, such as hormones, from secretory vesicles to the extracellular space.

Microtubules

The thickest cytoskeletal element, which can rapidly reorganize and is required to pull duplicated chromosomes to opposite poles during cell division.

Model organism

A subset of organisms chosen for study because they are easy to grow in lab conditions, have a rapid rate of reproduction, and are amenable to genetic manipulation.

E. coli

The bacterial species that played a central role in advancing the field of molecular biology.

Arabidopsis thaliana

A common weed selected as a model organism for flowering plants because it can reproduce in $8$ to $10$ weeks and produces thousands of offspring.

Drosophila melanogaster

An insect model organism that is the most abundant of all animal species.

Apoptosis

The process of programmed cell death, famously studied in $\text{C. elegans}$ where $131$ specific cells are destroyed during development.

Zebrafish (Danio rerio)

A model organism especially useful for studying early development because its embryos are transparent.

Mice

The best model system for studying human-related conditions, such as how specific genes affecting sugar metabolism might alter tooth development.