Origins of life Flashcards
1
Q
What are three properties of life?
A
- Organization - Response to stimuli
- energy use - Homeostasis
- reproduction - Growth and Development
- Evolve
2
Q
What is the smallest unit that has the properties of life?
A
The cell
3
Q
When was the earth formed?
A
4.5 billion years ago
4
Q
What was the reason for the appearance of oxygen?
A
Photosynthesis
5
Q
What were the earliest organisms?
A
Prokaryotes
6
Q
What are cyanobacteria?
A
Photosynthetic organisms
7
Q
What’s the difference between prokaryotes and eukaryotes?
A
Eukaryotes are larger and more complex
8
Q
Where the first plant, animal and fungi forms aquatic or land based?
A
Aquatic
9
Q
Where the first terrestrial creates prokaryotic or eukaryotic?
A
Prokaryotic
10
Q
What are the four stages of chemical evolution?
A
- Abiotic synthesis of small organic molecules
- Joining of these molecules into polymers
- Origin of boundaries
- Lifelike properties
11
Q
Protoboints precursors to ______ ?
A
Living cells
12
Q
Do protoboints reproduce precisely?
A
No
13
Q
How do cells store their genetic information?
A
In DNA
14
Q
What does RNA do?
A
It acts as a messenger carrying instructions from DNA to control protein synthesis
15
Q
RNA can also function as a(n) __________
A
Enzyme
16
Q
What is genetic material?
A
Materials found in the nucleus
17
Q
What does the plasma membrane do?
A
Regulates passage of molecules in and out of the cytoplasm
18
Q
What is the cytoplasm?
A
Fluid that fills the cell, consists of proteins, water and salt
19
Q
Why are cells relatively small?
A
As size increases, volume increases more rapidly
means longer diffusion time
20
Q
What is the cytoplasm surrounded by in a prokaryotic cell ?
A
Plasma membrane
21
Q
Does a prokaryotic cell have distinct interior components?
A
No
22
Q
List three traits of prokaryotic cells
A
Smaller and simpler then eukaryotes
mostly unicellular
Large variety of sized and shapes
23
Q
What characterizes eukaryotic cells?
A
An endomembrane system and membrane-bound organelles
24
Q
What are the organelles in eukaryotic cells?
A
Central vacuole Vesicles Endoplasmic reticulum Golgi apparatus Chromosomes Cytoskeleton Cell walls Nucleus Nucleolus
25
What do all cells of most multicellular organisms contain that are the same?
DNA
26
What is a genome?
The sum total of all gene types
27
What is a proteome?
The sum total of all protein types
28
What is the nucleus?
Storage for genetic material
29
What is the nucleolus?
Region of intensive ribosomal RNA synthesis
30
What are nucleopores?
Transports nucleic acids and proteins in and out of the cell nucleus
31
DNA of eukaryotes is divided into _______
Linear chromosomes
32
What are chromosomes associated with?
Packaging proteins and histones (form nucleosomes)
33
What are ribosomes?
RNA-protein complexes composed of two subunits that attach to messenger RNA
34
Where is the site of protein synthesis?
Ribosomes
35
What is the endomembrane cell?
It compartmentalizes cell into functional and structural components
36
What is the function of the rough endoplasmic reticulum?
Assembly of proteins (lots of ribosomes)
37
What is the function of the Smooth endoplasmic reticulum?
Makes lipids (no ribosomes)
38
Whats the difference between free ribosomes and bound ribosomes?
Free ribosomes: Suspended in the cytosol, Synthesize proteins that function within the cytosol
Bound ribosomes: Attached to the outside of the endoplasmic reticulum, synthesize proteins that are either included within membranes or exported from the cell
39
Does the endoplasmic reticulum account for half of the membranes material?
yes
40
What does the endoplasmic reticulum include?
Tubules and ribosomes
41
True or false:
| The E.R. is continuous with the nuclear membrane
True
42
What are three traits of the smooth E.R.?
1. Rich in enzymes
2. Important metabolic roles
3. Synthesize lipids
43
The smooth E.R. detoxifies ________
chemicals
44
What are glycoproteins?
A polypeptide to which an oligosaccharide is attached (many rough E.R. are glycoproteins)
45
Where do secreted proteins, in a rough E.R., get packaged?
Transport vesicles
46
Is the golgi apparatus in the endomembrane system?
Yes
47
What does the golgi apparatus do?
Collects, packages and distributes molecules synthesized at one location and utilized at another location
48
What is the golgi apparatus?
A collection of membrane sacs from the E.R.
49
What does the golgi modify?
Often glycosylations and non-cellulose polysaccharides
50
What do lysosomes do?
They digest components
51
What does the endomembrane system play a key role in?
The synthesis (and hydrolysis) of macromolecules in the cell
52
What does the mitochondria do?
Converts energy to forms useful for cells
53
What does the chloroplast do?
Converts energy to forms useful for cells
54
What's the difference between chloroplasts and mitochondrias?
Mitochondria: Performs respiration and is found in animal and plant cells
Chloroplasts: Performes photosynthesis and is found in plant cells
55
Chloroplasts synthesize __________
ATP
56
Are the mitochondria and chloroplasts found in the cytoplasm?
Yes
57
True or false?
The mitochondria has two membranes?
A smooth inner membrane and a highly folded membrane?
True
| True
58
What is the mitochondrial matrix?
A fluid-filled space inside the inner membrane
59
What does the inner membrane space of a mitochondria do?
This creates a fluid-filled space between the two membranes
60
What are plastids?
A generalized class of plant structures
61
What do amyloplasts do?
Store starch (plastids)
62
What do chromoplasts do?
Store pigments (plastids)
63
What do chloroplasts do and where can they be found?
Harness solar energy and turned it into sugar, leaves and other green structures of plants
64
What is chlorophyll and what does it do?
A green pigment, it absorbs light energy
65
Does the chloroplast have two membranes?
Yes
66
What are the chloroplasts two membranes?
One surrounds the stroma and the other are in the stroma and are called thylakoids (look like pucks)
67
What does the stroma contain?
DNA, ribosomes and photosynthetic enzymes
68
What do thylakoids hold?
Chlorophyll
69
What is endosymbiotic theory?
It explains the origin of eukaryotic cells from prokaryotes
70
What extends throughout the cytoplasm?
A network of fibres
71
What does the fibres in the cytoplasm do?
They organize the structure and activities of the cell
72
What is the cytoskeleton and what does it do?
A network of protein fibres that supports cell shape and anchors organelles
73
What is surrounded by the tonoplast?
Central vacuole
74
What are the three parts of the cell wall?
Primary walls, middle lamella and secondary walls
75
Can a single organism be comprised of more than one cell?
| What's the benefit?
Yes
| Division of labour
76
Larger genomes have potentially ________ proteomes
Larger
77
What can additional proteins be used for?
Cell communication, arrangement and attachment of cells, and cell specialization (tissues)
78
What is the extracellular matrix?
A network of material secreted from the cells to form a complex meshwork outside of cells
(secreted: produce and discharge)
79
Is the extracellular matrix a major component of certain parts of plants and animals?
Yes
(Bone and cartilage of animals)
(Woody parts of plants)
80
Structural proteins of the extracellular matrix are used in what?
Bones, cartilage, tendons and skin
81
Adhesive proteins in the extracellular matrix do what?
Helps cells adhere to the extracellular matrix
82
What do cell junctions do?
Adhere cells together as well as the extracellular matrix
83
In plants is cellular organization different from animals?
Yes, because plants have a rigid cell wall
84
Are anchoring junctions part of animal or plant cells?
Animal cells
85
What do anchoring junctions do?
Attach cells together and to the extracellular matrix
86
What three types of anchoring junctions are there?
1. desmonosomes
2. tight junctions
3. gap junctions
87
What do desmonosomes do?
Use large flat plates to hold the cell together
88
What do tight junctions do?
Formes a tight seal between adjacent cells
89
What do gap junctions do?
Small gap between plasma membranes of adjacent cells, allow passage of ions and small molecules
90
What is the plant cell wall and what are it's two components?
Protective layer outside the cytoplasm of plants
1. Primary cell wall
2. Secondary cell wall
91
Does the cell wall act as a extracellular matrix in plants?
Yes
92
What holds the primary cell walls of cells together?
The middle lamella (sticky sugars)
93
Plasmodesmata are functionally similar to gap junctions
True or False?
What's the difference between the two?
True
| Plasmodesmata are bigger than gap junctions
