Unit 2: Cells Flashcards
What is the difference between light and electron microscopes?
Light: pass visible light through a specimen and glass lenses bad light to magnify the image and project it to the viewers eye
Electron: use a beam of electrons
What is the difference between scanning electron microscopes and transmission electron microscopes?
Scanning electron microscopes: study the detailed architecture of cell surfaces
Transmission electron microscopes: study details of internal cell structure
Cell Theory
States: all living things are composed of cells and all living cells came from other cells
Do large cells have more/less surface area than small cells? How is it related to their volume?
Large cells have more surface area compared to small cells, but less related to their volume
What sets limits on a cells size?
The functions it must carry out. A cell must AT LEAST (minimum size)be able to house enough DNA molecules protein molecules, and internal structures to survive and reproduce. AT MOST (maximum size) a cell should have enough SA to get enough nutrients and oxygen and dispose of waste. Size is also limited to the distance materials must diffuse within a cell
What are the two types of cells found on earth?
Prokaryotic and eukaryotic
What kingdoms are found in both types of cells?
PROKARYOTIC: bacteria
EUKARYOTIC: plants, animals, fungi, and protists
What are 4 things all cells have in common?
- All bounded by a plasma membrane
- Have chromosomes carrying genes made of DNA
- Contain ribosomes
- Made of protein
Which type of cell (prokaryotic/eukaryotic) is usually bigger?
Eukaryotic
Nonmembranous organelles
- no membrane
- direct contact with the cytosol
- includes the cytoskeleton, microvilli, centrioles, cilia, ribosomes and proteasomes
Membranous organelles
- covered with phospholipid membrane
- isolated from the cytosol
- includes the ER, nucleus, Golgi apparatus, lysosomes, Peroxisomes, and mitochondria
Cytoplasm
Entire region between the nucleus and the plasma membrane
Chromosomes
Carry genes made of DNA. Has information for making proteins
Ribosomes
Makes proteins according to instructions from genes
Nucleus
Contains and protects genetic material (DNA)
Controls cells activities by directing protein synthesis
DNA in prokaryotes is round
DNA in eukaryotes is thread-like
Nucleoid
Where the DNA of a prokaryotic cell is contained. In a eukaryotic cell, there is not membrane that surrounds the DNA.
Flagella
Propels the prokaryotic cell through its liquid environment
4 differences between prokaryotic and eukaryotic cells
PROKARYOTIC:
- small
- no nucleus that stores DNA
- No membrane-enclosed organelles
- smaller and different ribosomes
EUKARYOTIC:
- larger
- membrane enclosed organelles
- has a nucleus
What are organelles?
Small organs that are membrane bound structured that perform specific functions in the cell
What are the 4 main functions carried out by organelles in the cells?
- Manufacturing (nucleus, ribosomes, ER, Golgi apparatus)
- Breakdown (lysosomes, vacuoles, peroxisomes)
- Energy (mitochondria, chloroplast)
- Structure/movement/communication (cytoskeleton, plasma membrane, cell wall)
Which structures are found in plant cells but not animal cells?
Central vacuole, chloroplast, cell wall, plasmaodesmata)
Cell wall
What is its function?
What is it made of?
Around the plasma membrane
Protects cells and maintains their shape
Composed of cellulose
Chloroplasts
Performs photosynthesis
What is the importance of the central vacuole in plant cells?
Store water and other various chemicals