Unit 4: Cells Flashcards
1
Q
Cell Theory
A
- All living things are made up of cells
- Sells are the basic units of structure and function
- New cells are produced by existing cells
2
Q
mirograph
A
a photo taken through a microscope
3
Q
Robert Hook
A
- 1665 = he used an early compound microscope to look at a thin slice of cork (plant material)
- he noted that the chambers looked like cells of a monastery
4
Q
Anton van Leeuwenhoek
A
- 1st to observe living cells in pond water
- 1st to observe and describe bacteria
5
Q
Matthias Schleiden
A
-1838 = concluded that all plants are made up of cells
6
Q
Theodor Schwann
A
-1839 = stated that all animals are made up of cells
7
Q
Rudolph Virchow
A
-1855 = concluded that new cells were created only from the division of existing cells
8
Q
electron microscopes
A
- reveal details 1,000 times smaller than those visible in light microscopes
- uses a beam of electrons instead of light
9
Q
election microscopy
A
-used to see only non-living preserved cells and tissues
10
Q
transmission electron microscopes (TEMs)
A
- used to study cell structures, large protein molecules, and the details of internal cell structure
- specimen must be cut into ultra thin slices and are stained with atoms of heavy metals, which attach to certain cellular structures more than others
- uses a beam of electrons
- they have truly revolutionized the study of cells and their structures
11
Q
scanning electron microscopes (SEMs)
A
- produce 3D images of cells
- used to study detailed architecture if cell surfaces
- specimen don’t have to cut into thin slices
12
Q
Prokaryotes
A
- unicellular
- cells don’t have nuclei
- have genetic material that isn’t contained in a nucleus
- doesn’t have membrane-bound organelles
- all are considered a type of bacteria (archeabacteria, eubacteria)
- generally smaller and simpler than eukaryotic cells
13
Q
Eukaryotes
A
- cells have nuclei
- the nucleus is where their genetic material is separated from the rest of the cell
- generally larger and more complex than prokaryotic cells
- mostly multicellular
- generally contain dozens of structures (organelles) and internal membranes
- Ex: plants, animals, fungi, protists
- highly specialized due to organelles
14
Q
Endosymbiosis
A
- theory that suggests that certain organelles were once free-living organisms
- it explains that origins of eukaryotic cells
- Evidences = mitochondria and chloroplasts have prokaryotic ribosomes and both copy themselves from cells; Each contains circular pieces from DNA like prokaryotes
15
Q
Cells
A
- a basic unit of living matter separated from its environment by a plasma membrane
- they are the fundamental structural unit of live
- come in a variety of shapes and sizes
- all cells are surrounded by a barrier called a cell membrane and at some point contain DNA
- cells are classified into 2 categories depending on whether they contain a nucleus
16
Q
nucleus
A
-large membrane-enclosed structure that contains the cell’s genetic material in the form of DNA and it contains many of the cell’s activities
17
Q
organelles
A
- “little organs”
- in the cytoplasm
- a membrane-enclosed structure with a specialized function within a cell
- the evolution of organelles creates a division of labor where every organelle had it’s own job
18
Q
light microscopes (LM)
A
- works by passing visible light through a specimen (microorganism or thin slice of animal tissue)
- the glass lenses in it bend the light to magnify the image of the specimen and project the image into the viewer’s eye or onto photographic film or a video screen
19
Q
magnification
A
-the increase in the apparent size of an object
20
Q
cytoplasm
A
-the entire region between the nucleus and the plasma membrane
21
Q
nucleoid
A
- where the DNA of a prokaryotic is coiled
- inside the nucleus
22
Q
ribosomes
A
-tiny structures that make proteins according to the instructions from the genes (DNA)
23
Q
chromosomes
A
- a threadlike,gene-carrying structure found in the nucleus of a eukaryotic cell and most visible during mitosis and meiosis
- the main gene-carrying structure of a prokaryotic cell
- they consist of chromatin and a combo of DNA and protien
- carry genes made of DNA
24
Q
flagella
A
- long projections/cellular appendages
- may propel the prokaryotic cell through its liquid environment
- specialized for locomotion (movement or ability to move from one place to another)
- the flagella of prokaryotes and eukaryotes differ in structure and function
- eukaryotic flagella have a 9+2 arrangement or microtubules covered by the cell’s plasm membrane
25
pili
- short projections
| - help attach prokaryotes to surfaces
26
plasma membrane
- membrane that sets a cell off from its surroundings and acts as a selective barrier to the passage of ions and molecules into and out of the cell (active and passive transport)
- consists of a phospholipid bilayer in which are embedded molecules of protein and cholesterol
27
the 4 basic functional groups the structures and organelles of eukaryotic cells can be organized into
1. the nucleus, ribosomes, enoplasmic reticulum, and Golgi apparatus function in manufacturing
2. organelles involved in breakdown or hydrolysis of molecules include lysosomes, vacuoles, and peroxisomes
3. mitochondria in all cells are involved in energy processing
4. structural support, movement, and communication among calls are functions of components of the cytoskeleton, plasm membrane and cell wall
28
cellular metabolism
the chemical activities of cells
29
lysosomes
- digestive organells in eukaryotic cells
| - contains hydrolytic enzymes that digest the cell's food and wastes
30
vacuoles
- membrane-enclosed sac that is part of the endomembrane system for a eukaryotic cell
- has diverse functions
31
peroxisomes
-organelle consisting of enzymes that transfer hydrogen from various substrates into oxygen, producing and then degrading hydrogen-peroxide
32
centrioles
- structure in an animal cell made up of cylinders of microtubule triplets arranged in a 9 and 0 pattern
- an animal usually has a centrosome with a pair of centrioles involved in cell division
33
plasmodesmata
-channels through cell walls that connect adjacent cells
34
chloroplast
- where photosynthesis occurs in plant cells
| - gives plants green color
35
cytoskeleton
- network of protein filled fibers in the cytoplasm of a eukaryotic cell
- includes microfilaments, intermediate filaments, and microtubes (and ribosomes)
- keeps the structure of the cell
