Hooke
first to identify cells and name them
Leeuwenhoek
observed live cells and observed in greater detail
Schleiden
concluded that plants are made of cells
Schwann
concluded that animals and all living things are made up of cells
Virchow
proposed that all cells come from other cells
What are the three parts of the cell theory?
1. all organisms are made of cells
2. all existing cells are produced by other living cells
3. the cell is the most basic unit of life
Two reasons why the cell theory is important
1. helped people understand that life didn't arise from nonliving sources
2. one of the great unifying theories of biology
Eukaryotic cells
- surrounded by a cell membrane
- contains cytoplasm
- contains a nucleus
- contains membrane-bound organelles
- tends to be microscopic in size
- may be single-celled or multicellular
Prokaryotic cells
- surrounded by a cell membrane
- contains cytoplasm
- tends to be microscopic in size
- single-celled
Both Eukaryotic and prokaryotic cells
- surrounded by a cell membrane
- contains cytoplasm
- tends to be microscopic in size
What is cytoplasm?
a jellylike substance that contains dissolved molecular building blocks and, in some types of cells, organelles
Where do you find organelles?
in the cytoplasm
What statements summarize scientist's concepts of cells?
cell theory
Which type of cells have no nucleus?
prokaryotic cells
What are the functions of a cytoskeleton?
supports and shapes the cell, positions and transports organelles, provides strength, assists in cell division, and aids cell movement
How is a cytoskeleton like your skeleton?
supports and shapes the cell
How is a cytoskeleton like your muscles?
helps the cell move
Nucleus function
stores most of the genetic information of a cell
Nucleus contains
the nucleolus
Nucleolus
where ribosomes are assembled
Endoplasmic reaction function
helps in the production of proteins and lipids
Ribosomes function
link amino acids together to form proteins
Golgi apparatus function
processes, sorts, and delivers proteins
Vesicles function
carries certain molecules from place to place within a cell
Mitochondrion function
supply energy to the cell by converting molecules from food into usable energy
Vacuole function
stores materials needed by a cell; may help provide support to plant cells
Lysosome function
contains enzymes that break down damaged and worn-out cell parts; defends a cell from invaders
Centriole function
organizes microtubules to form cilia and flagella for cell motion or the movement of fluids past a cell
What role do cell walls play in a plant?
They are strong and rigid and adhere to each other, which helps to support the entire plant
Cell membrane
- all cells are surrounded by a it
- is flexible and interacts with the environment
Cell wall
- only certain cells have a cell wall
- rigid and provides shape and support to the cells
Why are chloroplasts important?
They enable plants to convert solar energy into energy-rich molecules that cells can use
Which cell part is a maze of folded membranes where proteins and lipids are produced?
endoplasmic reticulum
Which cell part converts food into energy that is usable by a cell?
mitochondrion