Cellular structure and function Flashcards
1
Q
What is an active boundary?
A
A barrier that is constantly changing and responsive to the environment.
2
Q
What is aerobic respiration?
A
The breakdown of glucose to simple inorganic compounds in the presence of oxygen and with release of energy that is transferred to ATP.
3
Q
What is adenosine triphosphate (ATP)?
A
The common source of chemical energy for cells.
4
Q
What is Animalia?
A
A group of eukaryotic multicellular organisms whose cells lack a cell wall.
5
Q
What are archaea?
A
A group of prokaryotes that live in extreme environments; also known as extremophiles.
6
Q
What is autophagy?
A
Breakdown by lysosomes of non-functioning cell organelles that are old and/or damaged and in need of turnover.
7
Q
What are bacteria?
A
A group of prokaryotes that can reproduce by binary fission.
8
Q
What are biomacromolecules?
A
Large biological polymers such as nucleic acids, proteins, and carbohydrates.
9
Q
What is bulk transport?
A
The movement of material into a cell (endocytosis) or out of a cell (exocytosis).
10
Q
What is a capsule?
A
Polysaccharide layer outside the cell membrane for protection.
11
Q
What is a carrier protein?
A
Protein that binds to a specific substance and facilitates its movement through the membrane.
12
Q
What is a cell?
A
The basic functional unit of all organisms.
13
Q
What is cell theory?
A
Theory that all living things are made of cells.
14
Q
What is a cell wall?
A
Semi-rigid structure located outside the plasma membrane in the cells of plants, algae, fungi, and bacteria.
15
Q
What is a cell (plasma) membrane?
A
Partially permeable boundary of a cell separating it from its physical surroundings; boundary controlling entry to and exit of substances from a cell.
16
Q
What is cellular respiration?
A
Process of converting the chemical energy of food into a form usable by cells, typically ATP.
17
Q
What is cellulose?
A
Complex carbohydrate composed of chains of glucose molecules; the main component of plant cell walls.
18
Q
What are centrioles?
A
A pair of small cylindrical organelles, used in spindle development in animal cells during cell division.
19
Q
What are channel proteins?
A
Trans-membrane proteins involved in the transport of specific substances across a plasma membrane by facilitated diffusion.
20
Q
What is chitin?
A
A fibrous substance, mainly composed of polysaccharides, used in the cell walls of fungi.
21
Q
What is chlorophyll?
A
Green pigment required for photosynthesis that traps the radiant energy of sunlight.
22
Q
What is a chloroplast?
A
Chlorophyll-containing organelle that occurs in the cytosol of cells of specific plant tissues.
23
Q
What is cholesterol?
A
Sterol compound important in the composition of cell membranes.
24
Q
What are cilia?
A
In eukaryote cells, whip-like structures formed by extensions of the plasma membrane involved in synchronised movement; singular = cilium.
25
What is a colony?
Several individuals living together in close association.
26
What is a concentration gradient?
Occurs when there is a difference in solute concentration from one area to another.
27
What are covalent bonds?
A type of bond between atoms where electrons are shared. The bond is very strong.
28
What is crenation?
Shrinking of cell due to water loss.
29
What is cytoplasm?
Formed by cell organelles, excluding the nucleus, and the cytosol.
30
What is cytosol?
The aqueous part of the cell.
31
What is the cytoskeleton?
Network of filaments within a cell.
32
What is deoxyribonucleic acid (DNA)?
Nucleic acid containing the four bases — adenine, guanine, cytosine, and thymine — which forms the major component of chromosomes and contains coded genetic instructions.
33
What is the electron transport chain?
Third stage of aerobic respiration in which electrons are transferred along a series of compounds known as cytochromes to be finally accepted by oxygen; energy released during this process results in the major yield of ATP.
34
What is endocytosis?
Bulk movement of solids or liquids into a cell by engulfment.
35
What is the endoplasmic reticulum?
Cell organelle consisting of a system of membrane-bound channels that transport substances within the cell.
36
What is endosymbiosis?
A special case of symbiosis where one of the organisms lives inside the other.
37
What is the endosymbiotic theory?
See endosymbiosis; a theory proposed by Lynn Margulis.
38
What is a eukaryote?
Any cell or organism with a membrane-bound nucleus.
39
What is an exergonic reaction?
Energy-releasing chemical reaction.
40
What is exocytosis?
Movement of material out of cells via vesicles in the cytoplasm.
41
What is an extremophile?
Microbe that lives in extreme environmental conditions, such as high temperature and low pH.
42
What are flagella?
Whip-like cell organelles involved in movement; singular = flagellum.
43
What is the fluid mosaic model?
A model proposing that the plasma membrane and other intracellular membranes should be considered as two-dimensional fluids in which proteins are embedded.
44
What are fungi?
Any of a wide variety of organisms that have a cell wall made of chitin and reproduce by spores, including mushrooms, moulds, yeasts, and mildews.
45
What are glycolipids?
Small chains of carbohydrates (sugars) attached to the phospholipids and proteins of the plasma membrane; aid in cell recognition.
46
What is glycolysis?
A process that does not require oxygen, where glucose is broken down to pyruvate.
47
What are glycoproteins?
Combination formed when a carbohydrate group becomes attached to the exposed part of a trans-membrane protein.
48
What is the Golgi apparatus?
Organelle that packages material into vesicles for export from a cell (also known as Golgi complex or Golgi body).
49
What are grana?
Stacks of membranes on which chlorophyll is located in chloroplasts; singular = granum.
50
What are hydrophilic substances?
Substances that dissolve easily in water; also called polar.
51
What are hydrophobic substances?
Substances that tend to be insoluble in water; also called non-polar.
52
What does hypertonic mean?
Having a higher concentration of dissolved substances than the solution to which it is compared.
53
What does hypotonic mean?
Having a lower concentration of dissolved substances than the solution to which it is compared.
54
What are integral proteins?
Fundamental components of the plasma membrane that are embedded in the phospholipid bilayer.
55
What are intermediate filaments?
One of the components of the cytoskeleton of a cell, composed of protein; they form a rope-like arrangement and give mechanical support to cells.
56
What does isotonic mean?
Having the same concentration of dissolved substances as the solution to which it is compared.
57
What is kinetic energy?
The energy associated with movement.
58
What is the Krebs cycle?
Second stage of aerobic respiration, occurring mainly in mitochondria, in which pyruvate is broken down to carbon dioxide.
59
What is lignin?
A complex, insoluble cross-linked polymer.
60
What are lipophilic molecules?
'Lipid-loving' molecules that dissolve in lipids (hydrophobic).
61
What are lipophobic molecules?
'Lipid-fearing' molecules that do not dissolve in lipids (hydrophilic).
62
What is lysis?
Bursting of a cell.
63
What is a lysosome?
Vesicle filled with digestive enzymes.
64
What is a lysosome storage disease?
A disruption of normal cell function due to defective enzymes; examples include Tay–Sachs disease, Hurler syndrome, Pompe disease.
65
What is the major histocompatibility complex (MHC)?
A group of proteins that have a role in the detection of invaders.
66
What is a membrane-bound organelle?
An organelle that has a membrane surrounding it.
67
What is messenger RNA (mRNA)?
Single-stranded RNA formed by transcription of a DNA template strand in the nucleus; mRNA carries a copy of the genetic information into the cytoplasm.
68
What are microfilaments?
One of the components of the cytoskeleton of a cell; very thin threads composed of the protein actin; they allow cells to move and change in shape.
69
What is microscopic?
Anything that is not visible to the naked eye and requires a microscope to view it.
70
What are microtubules?
Part of the supporting structure or cytoskeleton of a cell, made of sub-units of the protein tubulin.
71
What are mitochondria?
In eukaryotic cells, organelles that are the major site of ATP production; singular = mitochondrion.
72
What is the nuclear envelope?
Membrane surrounding the nucleus of a eukaryotic cell.
73
What is the nuclear pore complex (NPC)?
Protein-lined channel that perforates the nuclear envelope.
74
What is a nucleic acid?
A compound, such as DNA or RNA, built from nucleotide sub-units.
75
What is a nucleolus?
A small, dense, spherical structure in a nucleus that is composed of RNA and produces rRNA.
76
What are nucleotides?
The basic building blocks or sub-units of DNA and RNA consisting of a phosphate group, a base, and a sugar.
77
What is a nucleus?
In eukaryotic cells, membrane-bound organelle containing the genetic material DNA.
78
What is an organelle?
Any specialised structure that performs a specific function.
79
What is an organism?
Any living creature.
80
What is osmosis?
Net movement of water across a partially permeable membrane without an input of energy and down a concentration gradient.
81
What is osmotic flow?
The net movement of water molecules from a solution of high water concentration to lower water concentration (or alternatively, from a region of low to high solute concentration).
82
What is peptidoglycan?
Polymer of sugars and amino acids that form a structure of protection outside the cell membrane of prokaryotes.
83
What are peripheral proteins?
Either anchored to the exterior of the plasma membrane through bonding with lipids or indirectly associated through interactions with integral protein.
84
What is a peroxisome?
Small membrane-bound organelle rich in the enzymes that detoxify various toxic materials that enter the bloodstream.
85
What is phagocytosis?
Bulk movement of solid material into cells.
86
What is a phospholipid?
Major type of lipid found in plasma membranes.
87
What is photosynthesis?
Process by which plants use the radiant energy of sunlight trapped by chlorophyll to build carbohydrates from carbon dioxide and water.
88
What is pinocytosis?
Bulk movement of material that is in solution being transported into cells.
89
What is Plantae?
A group of organisms that include land plants and algae. Cells have a cell wall of cellulose, a large permanent vacuole, and some contain chloroplasts.
90
What is a plasmid?
Small ring of DNA found in prokaryotes.
91
What is plasmolysis?
Shrinking of the cytoplasm away from the wall due to water loss.
92
What are polysaccharides?
Long chains of sugars joined together to form large molecules.
93
What is Pompe disease?
Lysosome storage disease where an absent or defective enzyme in the lysosomes does not break down glycogen and results in tissues with abnormal deposits of glycogen.
94
What are proteins?
Macromolecules built of amino acid sub-units and linked by peptide bonds to form a polypeptide chain.
95
What is protista (protists)?
A group of organisms similar in the fact that they do not fall into any other kingdom; generally unicellular; can have aspects of both plant and animal cells.
96
What is a prokaryote?
Any cell or organism without a membrane-bound nucleus.
97
What are pumps?
Special transport proteins embedded across the plasma membrane that carry out the process of active transport.
98
What is ribonucleic acid (RNA)?
Type of nucleic acid consisting of a single chain of nucleotide sub-units that contain the sugar ribose and the bases A, U, C, and G.
99
What is ribosomal RNA (rRNA)?
Ribosomal ribonucleic acid; synthesises proteins and is the primary component of ribosomes.
100
What is a ribosome?
Organelle containing RNA that is the major site of protein production in cells.
101
What is rough endoplasmic reticulum?
Endoplasmic reticulum with ribosomes attached.
102
What is selectively permeable (semipermeable)?
Allows some substances to cross but precludes the passage of others.
103
What is smooth endoplasmic reticulum?
Endoplasmic reticulum without ribosomes.
104
What is the sodium–potassium pump?
Protein that transports sodium and potassium ions against their concentration gradients to maintain the differences in their concentrations inside and outside cells.
105
What is a solute?
Substance that is dissolved.
106
What is a solution?
Liquid mixture of the solute in the solvent.
107
What is a solvent?
Liquid in which a solute dissolves.
108
What is stroma?
In chloroplasts, the semi-fluid substance between the grana, which contains enzymes for some of the reactions of photosynthesis.
109
What is the surface area to volume ratio?
A measure that identifies the number of units of surface area available to ‘serve’ each unit of internal volume of a cell, tissues, or organism.
110
What is tonoplast?
In plant cells, the membrane of the plant vacuole; separates it from the rest of the cytosol.
111
What is transcription?
Process of copying the genetic instructions present in DNA to messenger RNA.
112
What are trans-membrane proteins?
Spanning the plasma membrane but have parts exposed to the exterior and interior of the cells.
113
What is transfer RNA (tRNA)?
A molecule made of RNA that brings amino acids to the ribosome in protein synthesis.
114
What is translation?
Process of decoding the genetic instructions in mRNA into a protein (polypeptide chain) built of amino acids.
115
What does turgid mean?
Swollen and distended.
116
What is a vacuole?
Structure within plant cells that is filled with fluid-containing materials in solution, including plant pigments.
117
What is a vesicle?
Membrane-bound sac found within a cell, typically fluid-filled; for example, a lysosome.
