science test (cells) - feb 22 Flashcards
what is a prokaryotic cell?
single-celled organisms.
what is a eukaryotic cell?
multi-celled organisms.
what are organelles?
small structures that make up a cell
do both plant and animal cells have organelles?
while plant and animal cells have several of the same organelles, there are some structures that are found only in plants and not in animals.
where are organelles found?
many of the organelles found in cells are made up of or are surrounded by membrane and therefore would not be found in prokaryotic cells.
what is a cell membrane?
a plant and animal cell that forms outer boundary of cell; separates the cell from its environment. it also surrounds cytoplasm.
what is a cell membrane made up of?
a cell membrane is made up of lipids with some proteins scattered throughout. the proteins form tiny passageways in the membranes called pores.
what is the function of a cell membrane?
the function is to control what moves in and out of the cell and to provide protection and support for the cell. cell membranes help maintain homeostasis.
what is homeostasis?
the process of self regulation by organisms to maintain survival while adjusting to conditions best for survival.
what is the nucleus?
the nucleus is the largest organelle that is made up of three parts. the nuclear membrane, chromosomes, and the nucleolus.
what is the nuclear membrane?
a thin layer that surrounds the nucleus. it contains pores to let materials in and out.
what are chromosomes?
thin threadlike structures made up of DNA (controls cell activities and provides the information or “recipe” the ribosomes need to make proteins).
what is the function of the nucleolus?
makes ribosomes (which make proteins). controls all of the cells activities, controls which proteins are made.
what are ribosomes?
ribosomes are small grain like bodies (they are not covered in a membrane). they are both plant and animal cells.
what is the function of ribosomes?
they makes protein by getting instructions from the DNA in nucleus, the DNA gives the ribosomes codes that amino acids combine to make a special protein.
what is ER?
ER or endoplastic reticulum is a folded, tubelike membrane. rough ER has ribosomes on it; smooth ER lacks ribosomes. ER is an animal and plant cell.
what is the function for ER?
it moves materials especially protein around the cell, acts like a conveyor belt, is the cells transportation system.
what is cytoplasm?
a clear, thick, jelly like material. it contains a large amount of water (about 70%) and chemicals, may sometimes appear to be grainy this grain appearance comes from the organelles floating in it). cytoplasm is constantly moving or “streaming” through the cell.
where is cytoplasm found?
inside the cell membrane but outside the nucleus.
what is the function of cytoplasm?
contains all the organelles of the nucleus outside of the nucleus.
what is the cytoskeleton?
a web of long tubes and fibers made of protein.
what is the function of cytoskeletons?
to support the cell and help the cell keep its shape.
where is the cytoskeleton found?
the cytoskeleton can be found throughout the cytoplasm.
what are golgi bodies?
stacks of flat, membrane-covered sacs; looks a lot like smooth ER. the golgi body is a plant and animal cell.
