Organization and Structure of Cells Flashcards
1
Q
- most abundant organisms on earth
- bacteria or green algae
A
prokaryotes
2
Q
a prokaryotic cell does not contain a ___ __
A
membrane-bound nucleus
3
Q
Shapes of bacteria
A
- cocci (spheroidal)
- bacilli (rod like)
- spirilla (helically coiled)
4
Q
Two groups of bacteria
A
- eubacteria
- archaebacteria
5
Q
cocci
A
spheroidal
6
Q
bacilli
A
rod-like
7
Q
spirilla
A
helically coiled
8
Q
- relatively simple, single-celled (unicellular organisms)
- prokaryotes
- generally appear in one of several shapes
- some are star shaped, or square
A
bacteria (s: bacterium)
9
Q
individual bacteria may form __, __, __ or other __
- such formations are usually characteristic of a particular genus or species of bacteria
A
- pairs
- chains
- clusters
- other groupings
10
Q
bacteria are enclosed in cell walls that are largely composed of a carbohydrate and protein complex called __
A
peptidoglycan
11
Q
bacteria are classified according to their cell wall as __ or __
A
- Gram-positive
- Gram-negative
12
Q
In Gram-positive bacteria, the peptidoglycan forms a __ (__) layer external to the cell membrane and may contain other macromolecules
A
thick (20-80 nm)
13
Q
In Gram-negative bacteria, the peptidoglycan layer is __ (__) and is overlaid by an outer membrane of lipopolysaccharides and lipoprotein
A
thin (5-10nm)
14
Q
Gram-negative bacteria are overlaid by an __ of __ and __
A
- outer membrane
- lipopolysaccharide
- lipoprotein
15
Q
peptidoglycan (__ and __) cell wall protects the bacteria from __ and __ __
A
- protein and oligosaccharide
- mechanical and osmotic pressure
16
Q
What is between the outer membrane and the cell wall in Gram-negative bacteria?
A
periplasm
17
Q
what occupies the periplasm
A
proteins secreted by the cell
18
Q
consists of a lipid bilayer containing embedded proteins that control the passage of molecules in and out of the cell and catalyzes a variety of reactions
A
plasma membrane
19
Q
infoldings of the plasma membrane in bacteria
A
mesosomes
20
Q
the deoxyribonucleic acid (DNA) is condensed within the __ to form the __
A
- cytosol
- nucleoid
21
Q
some prokaryotes have tail-like __
A
flagella
22
Q
how do bacteria generally reproduce
A
binary fission
23
Q
what do bacteria use for nutrition
A
organic chemicals
24
Q
gram-negative bacteria
A
- outer membrane
- peptidoglycan layer
25
gram-positive bacteria
- no outer membrane
- thicker peptidoglycan layer
26
cyanobacteria
- gram-negative
- tougher peptidoglycan layer
- extensive internal membrane system with photosynthetic pigments
27
archaebacteria
- no outer membrane
- no peptidoglycan layer outside plasma membrane
28
- surface-associated adhesion amphiphile from Gram-positive bacteria and regulator of autolytic wall enzymes (muramidases)
- important cell wall polymer found in gram-positive bacteria
Lipoteichoic acid (LTA)
29
- consists of prokaryotic cells
- walls lack peptidoglycan
- often found in extreme environments and divided into three main groups
- not known to cause disease in humans
Archaea
30
Three main groups of archaea
1. methanogens
2. extreme halophiles
3. extreme thermophiles
31
produce methane as waste product form respiration
methanogens
32
live in extremely salty environments such as the Great Salt Lake and Dead Sea
extreme halophiles
33
examples of environments extreme halophiles live in
- Great Salt Lake
- Dead Sea
34
live in hot sulfurous water, such as hot springs at Yellowstone National Park
extreme thermophiles
35
example of an environment extreme thermophiles live in
hot springs at Yellowstone National Park
36
Thermophiles also color __ __ shown at Firehole Spring
hydrothermal features
37
have a membrane-bound nucleus and a number of other membrane-bound subcellular (internal) organelles, each of which has a specific function
eukaryotes
38
surrounds the cell, separating it from the external environment
plasma membrane
39
plasma membrane is a __ __ __ due to the presence of specific transport proteins
selectively permeable barrier
40
plasma membrane is involved in receiving information when __ bind to the receptor proteins on its surface, and in the processes of __ and __
- ligands
- exocytosis
- endocytosis
41
stores the cell's genetic information as DNA in chromosomes
nucleus
42
site of ribosomal ribonucleic acid (rRNA) synthesis
nucleolus
43
the nucleolus is the site of __ synthesis
ribosomal ribonucleic acid (rRNA)
44
large, dynamic structure that serves many roles in the cell including calcium storage, protein synthesis and lipid metabolism.
endoplasmic reticulum
45
Two distinct part of the endoplasmic reticulum
1. Rough endoplasmic reticulum (RER)
2. Smooth endoplasmic reticulum (SER)
46
- studded with ribosomes
- site of membrane and secretory protein biosynthesis and their post-transcriptional modification
Rough Endoplasmic Reticulum (RER)
47
- involved in phospholipid biosynthesis
- detoxifies toxic compounds
Smooth Endoplasmic Reticulum (SER)
48
- system of flattened membrane-bound sacs
- sorting and packaging center of the cell
Golgi apparatus
49
Golgi apparatus receive membrane vesicles from the __, further modifies the protein within them, and then packages the modified proteins in other vesicles which eventually fuse with the plasma membrane or other subcellular organelles
Rough Endoplasmic Reticulum (RER)
50
- have an inner and outer membrane separated by the intermembrane space
- generate most of the chemical energy needed to power the cell's biochemical reactions
- chemical energy produced is stored in a small molecule called adenosine triphosphate (ATP)
mitochondria
51
In mitochondria, the __ __ is more permeable than the inner membrane due to the presence of porin proteins
outer membrane
52
why is the outer membrane of mitochondria more permeable
presence of porin proteins
53
- folded to form cristae
- site of oxidative phosphorylation
- produces ATP
inner membrane
54
folds of the mitochondrial inner membrane
cristae
55
the mitochondrial inner membrane is the site of __ __
oxidative phosphorylation
56
site of fatty acid degradation and citric acid cycle
central matrix
57
central matrix of mitochondria is the site of __ __ __ and __ __ __
- fatty acid degradation
- citric acid cycle
58
- bounded by a single membrane
- degrades macromolecules
lysosomes
59
internal pH of lysosomes
pH 4-5
60
enzymes within lysosomes that are involved in the degradation of macromolecules, including those internalized by endocytosis
acid hydrolases
61
soluble part of the cytoplasm where a large number of metabolic reactions take place
cytosol
62
within the cytosol is the __, a network of fibers that maintain the shape of the cell
cytoskeleton
63
network of fibers that make up the cytoskeleton
- microtubules
- intermediate filaments
- microfilaments
64
- contain enzymes involved in the break down of amino acids and fatty acids
- has a by-produce to hydrogen peroxide
peroxisomes
65
by-product of peroxisomes
hydrogen peroxide
66
what degrades the hydrogen peroxide in peroxisomes
enzyme catalase
67
- made up of polysaccharide cellulose
- rigid, external layer that is specifically designed to provide structural support and rigidity
plant cell wall
68
in woody plants, the phenolic polymer called __ gives the cell wall additional strength and rigidity
lignin
69
- surrounded by a double membrane
- have an internal membrane system of thylakoid vesicles that are stacked up to form grana
chloroplast
70
contain chlorophyll and are the site of photosynthesis
thylakoid vesicles
71
stacked up thylakoid vesicles
grana
72
- where carbon dioxide (CO2) fixation takes place
- soluble matter around thylakoid vesicles
stroma
73
- used to store nutrients and waste products
- has an acidic pH
- creates turgor pressure inside the cell as it pushes out against the cell wall
plant cell vacuole
74
pressure that is exerted by the fluid (e.g. water) against the cell wall
turgor pressure
75
Prokaryotes:
DNA
in nucleoid region
76
Eukaryotes:
DNA
within membrane-bund nucleus
77
Prokaryotes:
Size
usually smaller
78
Eukaryotes:
Size
usually larger
79
Prokaryotes:
organization
usually single-celled
80
Eukaryotes:
organization
often multicellular
81
Prokaryotes:
metabolism
may not need oxygen
82
Eukaryotes:
metabolism
usually needs oxygen
83
Prokaryotes:
organelles
not membrane-bound
84
Eukaryotes:
organelles
membrane-bound
85
Within eukaryotic cells are __ and __ cells
- plant
- animal
86
structural similarities of plant and animal cells
- plasma membrane
- genetic mechanisms
- most organelles
87
structural differences of plant and animal cells
plants
- have chloroplasts, a large central vacuole and cell wall
- do not have centrioles
- have plasmodesmata
animal
- have gap junctions
88
- gated plant cell wall channels that allow the trafficking of molecules between cells
- play important roles during plant development and in the orchestration of cellular and systemic signaling responses during interactions of plants with the biotic and abiotic environment
Plasmodesmata (PD)
89
physiological differences of plant and animal cells
- plants: photosynthesis
- plants: cell plate during mitosis
- plants: starch, animal: glycogen
- plants: large central vacuole stores more water and carbohydrates
