Cells Flashcards
modern cell theory
- all living things are composed or made up of cells, which are the most basic unit of life
- cells are products of reproduction of pre-existing cells
- cells pass hereditary information (DNA) to their offspring cells
- cells have similar chemical compositions compared to other cells
- cells are the sites of energy flow mechanisms such as respiration
lowest level of structure capable of performing all the activities of life
basic units of structure and function
cells
coined the name cell in 1665
robert hooke
discovered various single-celled organisms in pond water and observed blood cells and sperm cells of animals
anton van leeuwenhoek
recognized cells as basic units of life
matthias schleiden and theodor schwann
two statements of cell
“all living things consist of cells”
“all cells come from pre-existing cells”
prokaryotes (genetic information)
DNA is round and flows freely in cytoplasm
eukaryotes (genetic information)
DNA is helix-shaped and straight, found in cytoplasm
prokartyotes (organelles)
DNA, plasma membrane, nucleoid, cytoplasm
eukaryotes (organelles)
membrane-bound organelles (mitochondria, chloroplasts (found only on plant cells), golgi body and endoplasmic reticulum
prokaryotes (cell wall)
present, composed of peptidoglycans
eukaryotes (cell wall)
can be found in plant and fungal cells but not composed of peptidoglycans
prokaryotes (size)
small (1-5 um)
eukaryotes (size)
can’t be found in animals
larger (10-100 um)
prokaryotes (organisms)
bacteria and archaea
eukaryotes (organisms)
animals, plants, fungi, and protists
prokaryotes (cell structure)
unicellular
eukaryotes (cell structure)
can be unicellular or multicellular
separates a cell from other cells and from surrounding fluids
holds cell together and give its shape
selectively permeable membrane
controls the movement of substances across it
cell membrane
cell membrane is also known as
plasma membrane
control center of the cell
houses genetic material
nucleus
contains a dense, protein-rich protoplasm
nucleoplasm
where ribosomes are formed
nucleus
fine strand structures spread through the nucleoplasm
the for of genetic material is present in when a cell is NOT dividing
chromatin
condensed chromatin structures that are visible when the cell is dividing
carriers of hereditary messages in the cells
chromosomes
surrounds the nucleus
separates the nuclear material from the cytoplasm
nuclear membrane
cell materials outside the nucleus
contains the highly organized organelles which take part in specific chemical activities
gel-like substance that fills the cell; site of most biochemical reactions
cytoplasm
free-floating or attached; site of protein synthesis
made up of ribosomal RNA and protein
ribosome
extensive system of membranes in the cytoplasm that is connected to the nuclear membrane
plays a major role in PRODUCTION, PROCESSING AND TRANSPORT of proteins and lipids
endoplasmic reticulum
site of protein synthesis
has ribosomes on the surface
synthesizer of membranes and proteins
rough ER
functions in the synthesis of lipids (production of steroids, phospholipids), carbohydrate metabolism (like in liver), detoxification of drugs and poisons (like in liver) and has none or few ribosomes on surface
smooth ER
site of lipid synthesis and carbohydrate metabolism
smooth ER
modifier, sorter, and shipper of materials throughout the cell
finishes, sorts and ships cell products
receives proteins from the ER and ships these to specific destination
consists of flattened membranous sacs
golgi apparatus
digests cellular materials
found in cytoplasm of most animal cells
contains digestive enzymes that break down food particles taken by phagocytosis (ingest large particles)
lysosomes