Chapter 3 Flashcards
1
Q
Explain Robert Hooke fully
A
- English physicist who melted spun glass to create lenses
- Focused on bee stings; fish scales; fly legs and any type of insect he could hold
- First person to see cells
- Discovered and initiated a new science, cell Biology
2
Q
Explain Antony van Leeuwenhoek
A
- Holland
- Improved lenses further
- Created earliest microscopes
- 1st objectives = tartar scraped from his teeth
- Viewed bacteria and protists others didn’t know existed and described microscopic parts of larger animals like blood cells
- Perpetuated the tea of spontaneous generation : suggests life arises from non-living matter / nothing
3
Q
Explain the cell theory fully
A
- Scottish surgeon, Robert Brown noted a roughly circular object in cells from orchids
- Saw the structure in every cell then identified it in cells of a variety of organisms
- Named it the nucleus
- Soon microscopists distinguished the translucent moving material that made up the res of the cell calling it the cytoplasm
4
Q
Explain Matthias and Theodore
A
- German biologist and Th. proposed new theory based on many observations made with microscopes
- Schleiden first observed that cells are the basic unit of life and Schwann compared animal cells to plant cells
- After seeing similarities in many cells they formulated a cell theory which originally had 2 components :
- All organisms are made up of one or more cells
- The cell is the fundamental unit of life
- Rudolf Virchow added third component : all cells come from preexisting cells
5
Q
What are the additional ideas in modern cell theory
A
- All cells have the same basic composition
- All cells use energy
- All cells contain DNA that is duplicated and passed on as each cell divides
6
Q
Explain light microscopes
A
- Generating true colour views of living pr preserved cells
- Light passes through object to reveal internal features
- Uses 2 or more lenses to focus visible light through specimen
- Can magnify up to 1600x
- Specimens must be transparent or thinly sliced
7
Q
Explain transmission electron microscopes
A
- Sends a beam of electrons through a very thin slice of a specimen
- It uses a magnetic field rather than a glass lens to focus the beam
- Can magnify up to 50 million x
- Microscope translates constrats in electron transmission into a high resolution 2D image showing internal features
8
Q
Explain scanning electron microscope
A
- Scans a beam of electrons over the surface of a metal coated 3D specimen
- Lower resolution than TEM and max magnification is 250 000 x
- Main advantage ability to highlight crevices and textures on specimen surface
9
Q
What are the features all cells have in common
A
- DNA : cells genetic info
- RNA : Instrumental in protein synthesis
- Ribosomes: manufactures proteins
- Cytoplasm : includes all cells contents
- Proteins : carry out all the cells work
- Cytosol : fluid portion of cytoplasm
- Lipid-rich cell membrane : forms boundary between the cells and its environment
10
Q
What are life’s 2 domains initally
A
- Prokaryotes = simplest and most ancient forms of life are those who lack a nucleus
- Eukaryotes = contains a nucleus
11
Q
What are life’s recent domains
A
- Bacteria
- Archaea
- Eukarya
12
Q
Explain Domain Bacteria
A
- Most abundant and diverse organisms
- Cause illness others = good for health and found on the skin and intestinal tract
- Structurally simple
- Circular DNA molecule = in nucleiod
- Rigid cell wall surrounds cell membrane protecting it from bursting from absorbing too much water
- Many can swim in fluid using flagella
- Fatty acids
- The nucleiod id the area where the cells circular DNA molecule congregates
13
Q
Explain Domain Archaea
A
- Structurally very similar to bacteria that differ in the composition of their phospholipids; cell walls and flagella
- No nucleus and membrane bound organelles
- Nonfatty acid lipids
- Most have cell walls and flagella is common; small than most eukaryotic cells
14
Q
Explain Domain Eukarya
A
- Larger in size
- Cytoplasm divided into organelles which carry out specific functions
- Nucleated
- Elaborate system of membranes creates organelles
- Fatty acids
15
Q
What did Carl Woese do
A
- 1977
- Studied key molecules in many cell types and detected differences suggesting that prokaryotes actually include 2 forms of life that are distantly related to each other
16
Q
What is bacteria valuable in
A
- Research; food processing and pharmaceutical production
- Critical role as decomposers in the ecosystem
17
Q
What were the first organisms described
A
- Microbes that use CO2 and Hydrogen to produce Methane
- From Domain Archea
18
Q
Explain Domain Eukarya in more detail ( plants and animals; difference in features)
A
- From microscopic protists to enormous whales
- Features that make them different to prokaryotic cells are :
- Have a large size ( 10 to 100 times greater )
- Cytoplasm in eukaryotic cells is divided into organelles compartments that carry out specials functions
- Animal and plant cells have many structures in common but also have some differences
- Plant cells have chloroplast and cell wall whereas animal cells don’t
19
Q
A membrane separates each cell from its surroundings
A
- Cell membrane
- Common in all cells
- Separates the cytoplasm from the cells surroundings
- Common in all cells
- In eukaryotic cells, the internal membranes enclose the organelles
- Cell membrane is composed of phospholipids : organic molecules that resemble triglycerides but with only 2 fatty acids instead of 3
20
Q
What is a phospholipid made up of
A
- 3 Subunits :
A glycerol attached to a hydrophillic phosphate head and 2 hydrophobic fatty acid tails
21
Q
Explain the phospholipid bilayer fully
A
- Forms the cell membrane
- Inside and outside of the cell the environment is aqueous ( there is water )
- The hydrophobic fatty acid tails are directed away from the water
- Semi permeable due to hydrophobic middle portion
- Lipids and small, non-polar molecules such as O2; CO2 pass freely in and out of the cell
- Fatty acid tails at the bilayers interior block ions and polar molecules such as glucose from passing through
22
Q
What else does the cell membrane consist of
A
- Not only phospholipid bilayer but also proteins and other molecules
23
Q
Explain the plasma membrane
A
- AKA fluid mosaic
- Explains the stricture of the plasma membrane of animal cells as a mosaic of components such as phospholipids; proteins; cholesterol and carbohydrates
- These give a fluid character to the membranes
24
Q
What do steroid molecules do
A
- Maintain the cell membranes fluidity as the temperature fluctuates
25
Q
What do phospholipids and proteins do together
A
- Provide the membranes structure
- Proteins are especially important to its function
- Some proteins extend through the phospholipid bilayer whereas others face only the inside to the outside of the cell
26
Q
What proteins do cells have in the membranes
A
- Transport proteins
- Enzymes
- Recognition protein
- Adhesion proteins
- Receptor proteins
27
Q
Explain Transport proteins fully
A
- Embedded in the phospholipid bilayer
- Creates passages through which ions; glucose and other polar substances pass into or out of the cell
28
Q
Explain enzymes fully
A
- Facilitate chemical reactions that would otherwise proceed too slowly to sustain life
- Are organic molecules that catalyse chemical reactions with being consumed
- Not all are associated with the membrane
29
Q
Explain recognition protein fully
A
- Carbs are attached to the cell surface proteins serve as name tags that help the body immune system recognise its own cells
- The immune system will attack cells with unfamiliar surface molecules
30
Q
Explain adhesion proteins fully
A
- Enable cells to stick to one another
31
Q
Explain receptor proteins fully
A
- Bind to molecules outside the cell and trigger an internal response called signal transduction
32
Q
Explain how eukaryotic cells divide labour fully
A
- Organelles have specialise functions that carry out the work of the cell
- Each has a unique set of proteins and other molecules that fit that organelles functions=
- The walls of these organelles are membranes, folded with enzymes and proteins
- Many of cells internal membranes for a co-ordinated endomembrane system
33
Q
Explain the endomembrane system fully in prokaryotic cells
A
- Consists of several interacting organelles
- The nuclear envelope; endrplastic reticulum; Golgi apparatus; lysosomes; vacuoles and cell membrane
- Interactions between the organelles of the endomembrane system enable cells to produce; package and release complex mixtures of biochemicals
34
Q
What organelles are essential for prokaryotic cells
A
- Cytoplasm
- DNA
- Free floating ribosomes
- Cell membrane
- Inclusion bodies ( complex molecules that are made up of lipids or sugars)
- Flagella
35
Q
What other organelles do eukaryotic cells have
A
- ER
- Lysosomes
- Mitochondria
- Golgi apparatus
36
Q
Explain the endomembrane system fully in eukaryotic cells
A
- Consists of several interacting organelles
- The nuclear envelope; ER ; Golgi apparatus; lysosomes; vacuoles and cell membrane
- Interactions between the organelles of the end-membrane system enables cells to produce; package and release complex mixtures of biochemicals
37
Q
Explain the cytoplasm fully
A
The watery mixture that occupies much of the cell’s volume; in eukaryotic cells it consists of all materials including organelles between the nuclear envelope and the cell membrane
38
Q
Explain the cytosol fully
A
The fluid portion of the cytoplasm
39
Q
Explain the cytoskeleton fully
A
Framework of protein rods and tubules in eukaryotic cells
40
Q
Explain Louis Pasteur
A
- 1859
- Finally disproved the idea of spontaneous generation
41
Q
Explain the Golgi Apparatus
A
- A sack of flat, membrane enclosed sacks that function as a processing centre
- Proteins from the ER pass through the Golgi sacs, complete intricate folding and becomes functional
- Enzymes in the GA also manufacture and attach carbs to proteins or lipids forming Glycoproteins or Glycolipids
- GA sorts and packages material into vesicles
- Move toward the cell membrane
Some materials become part of the membrane while others are secreted from the cell
42
Q
Explain ER fully
A
- Proteins destined for cell membrane or secretion - entire complex of ribosomes, mRNA and partially made protein anchors to the surface of ER
- A network. of sacs and tubes composed of membranes
- Originates at nuclear envelope and winds throughout the cell
- Close to nucleus surface studded with ribosomes making proteins that enter the inner compartment of the ER ( Rough ER )
- These proteins destined for secretion
- Adjacent to rough ER, Smooth ER, synthesises lipids and other membrane components, house enzymes that detoxify drugs and poisons
43
Q
Explain vesicles
A
- Lipids and proteins made by the ER exit the organelles in them
- Transport their contents to GA
44
Q
Explain the nucleus fully
A
- Core of the cells
- Functions like the brain of the cells
- Contains the cell’s DNA
- The nucleus controls or determines our identity
45
Q
Explain the Mitochondria fully
A
- Powerhouse of the cell
- Carries out the metabolic chain reactions that produce Adenosine Triphoshate ( biological form of energy )
- The heart has the most organelles
46
Q
Define ATP
A
The energy currency of the cell
47
Q
Explain the ribosomes fully
A
- Have no membrane but still important
- Make protein and work with ER
- Found in both prokaryotes and eukaryotes
48
Q
Explain Rough ER
A
- Connected to the nuclear membrane
- Have numerous ribosomal particles lined up throughout their surface
- Make proteins
49
Q
Explain smooth ER fully
A
- Does not have ribosomes and is responsible for the production of lipids and fats
50
Q
Explain lysosomes fully
A
- Organelles containing enzymes that dismantle and recycle food particles; captured bacteria; worn-out organelles and debris
- Called lysosomes because their enzymes lyse or cut apart their substrate
- GA detects these enzymes by recognising a sugar attached to them, then packages them into vesicles that eventually become lysosomes
51
Q
Explain the flagella and cilia fully
A
- Long, whiplike appendages that a cell uses for motility
- Short and numerous, movable protein projections extending from a cell
52
Q
Explain the centrosome fully
A
- Part of the cell that organises microtubules
53
Q
How does the cytoskeleton support eukaryotic cells
A
- The cytosol of eukaryotic cells contains a cytoskeleton, an intricate network of protein tracks and tubules
- A structural framework with many functions
- Aids in cells division - Helps connect cells to one another - Enables cells or parts of cells to move - Transportation system, structural support necessary to maintain 3D shape
54
Q
What are the 3 major parts of the cytoskeleton
A
- Microfilament
- Microtubules
- Intermediate filaments
