Module 1: Introduction to Cell Biology and The Cell Theory

Who made the first observation of cells and was was the observation

Robert Hooke observed empty walls from dead cells. Described chambers of cork as cells

Who was the light microscopist to observe cells and what was the observation

Anton van Leeuwenhoek observed “animalcules” in pond water

what did schleiden say about the cell theory

all plant tissues composed of cells. plant embroys arise from single cell

what did Schwann say about cell theory

all animals are made up of cells (Schleiden finding but for animals), plans and animals are similar

what did Virchow say about cell theory

cells can arise only from pre existing cells

what are the 3 tenets of the cell theory

1. all living organisms are composed of one or more cells

2. each cell is the structural and functional unit of life

3. cells can arise only from pre-existing cells

what are 3 exceptions to cell theory

viruses, viroids, prions

why are viruses an exception to cell theory

inert (outside a living cell) and a host is needed for reproduction even though they have nucleic acids with protein coat

why are viroid an exception to cell theory

need host machinery to replicate

what are prions and why are they an exception to cell theory

proteinaceous infectious particles, exception because they have no nucleic acids

what is the cytoplasm

all contents inside of the cell membrane (jelly + organelles)

what is the cytosol

jelly internal fluid environment of a cell (cytoplasm without organelles). has water, ions, molecules

what are the 8 basic properties of cells

1. organized and enclosed

2. genetic program

3. reproduce (duplicate genetic info)

4. get and use energy

5. fulfill chemical reactions

6. engage in mechanical activities

7. respond to stimuli

8. self-regulate 

define prokaryote and what are the domains

nucleus lacking and no membrane-bound organelles, includes bacteria and archaea domains (most abundant organism)

define eukaryote and what are the domains

“true” (has) nucleus and membrane bound organelles, has cytoskeleton and endomembrane system. includes eukarya domain

what is the central dogma

dna to rna (transcription) to protein (translation)

Features of bacteria domain

single circular chromosome called a plasmid, has many. has a cell wall surrounding cell membrane

features of archaea domain

isoprenoid cell membrane, inhabit extreme environments

what do prokaryotes rely on for support

cell wall and internal protein framework

what are the 4 kingdoms within the eukaryote domain

protists, fungi, plants, animals

protist kingdom features

diverse, mostly unicellular but some form colonies eg water molds

fungi kingdom features

chitin (polysaccharide) cell walls, heterotrophs (get energy from environment)

plant kingdom features

multicellular, polysaccharide cell walls, large vacuoles, plasmodesmata, autotrophic (make energy) 

what are plasmodesmata

connect neighboring plant cells

animal kingdom features

multicellular, no cell walls, heterotrophs, distinct early development

what is the role if the cytoskeleton

provides internal support. All eukaryotes have microfilaments and microtubules and only animals have intermediate filaments

what is a microfilament

double helix of actin monomers in cytoskeleton. aids cell movement and shape changes

what is an intermediate filament

strong fiber composed of protein subunits. internal mechanical support for the cell

what is a microtubule

hollow tube formed from tubulin dimers

what makes up the endomembrane system

nuclear envelope, endoplasmic reticulum, golgi apparatus, vesicles, lysosome, cell membrane

what is the role of the nuclear envelope

defines boundary of the nucleus. contains inner and outer membrane with nuclear pores connecting the two

structure and function of the endoplasmic reticulum

network of interconnected tubes and flat sacs. it is involved in protein and lipid synthesis

rough endoplasmic reticulum function

has ribosomes. makes transmembrane proteins, proteins that end up in the interior of organelles, and secreted proteins 

smooth endoplasmic reticulum function

site of fatty acid and phospholipid synthesis. enzymes within can convert cholesterol into steroid horomones and detoxify lipid-soluble drugs and metabolic products

golgi apparatus function

modifies proteins, sorts, and adds carbohydrates to proteins and lipids from the ER

what are the “pancakes” of the Golgi apparatus called

cisternae

what is the primary means for proteins and lipids to move to, around, and from the golgi apparatus

vesicles

role of mitochondria

produce energy in form of ATP

structure and function of lysosome

membrane-bound sacs containing digestive enzymes. garbage disposal

peroxisomes structure and function

spherical, oxidizes fatty acids and detoxifies toxic compounds (eg hydrogen peroxide)

what are model organisms

non-human species that are used for research to understand biology in simpler and accessible ways

what is an example of a model organism

mouse, worm, fly