Biology Module 1 Flashcards
(124 cards)
1
Q
What are the basic structural and functional units of life?
A
Cells
Cells make up all organisms.
2
Q
How are cells classified?
A
As either Prokaryotic or Eukaryotic
Example: red blood cells.
3
Q
What are the three principles of Cell Theory?
A
- Cells are the basic unit of life
- All living things are made up of cells
- All cells came from pre-existing cells
4
Q
What is a Scientific Theory?
A
A broad general explanation supported by a large amount of evidence
It is not a fact and can be modified if new evidence arises.
5
Q
What theory predicted that living creatures came from non-living material?
A
Theory of spontaneous generation
Example: maggots appeared on rotting meat.
6
Q
Who first observed cells and in what year?
A
Robert Hooke in 1665
He discovered a honeycomb structure in cork.
7
Q
What did Anton Van Leeuwenhoek observe?
A
The first living cell in pond water
This observation occurred in 1670.
8
Q
What significant discovery did Robert Brown make?
A
He discovered the nucleus in plant cells in 1833.
9
Q
Who proposed that all plant tissues are composed of cells?
A
Mattias Jakob Schleiden in 1838.
10
Q
What did Theodor Schwann conclude in 1839?
A
That animal tissues are also made up of cells.
11
Q
Who discovered that sperm and eggs are made of cells?
A
Albrecht von Roelliker in 1840.
12
Q
What did Carl Heinrich propose about cells in 1845?
A
That cells are the basic unit of life.
13
Q
Who added the third part of the cell theory and when?
A
Rudolf Virchow in 1855
He proposed that cells come from existing cells.
14
Q
What are the main differences between prokaryotic and eukaryotic cells?
A
- Prokaryotic: Unicellular, smaller, no nucleus
- Eukaryotic: Multicellular, larger, has a nucleus
15
Q
What is the size range of prokaryotic cells?
A
0.1 - 5 µm.
16
Q
What type of reproduction do prokaryotic cells undergo?
A
Asexual reproduction.
17
Q
What type of reproduction do eukaryotic cells undergo?
A
Sexual or Asexual reproduction.
18
Q
What is the main method of cell division in prokaryotic cells?
A
Binary fission.
19
Q
What is the main method of cell division in eukaryotic cells?
A
Mitosis or Meiosis.
20
Q
What structures are found in prokaryotic cells?
A
- Cell wall
- Pili
- Flagella
- Capsule
21
Q
What are the main components of a compound light microscope?
A
- Eyepiece Lens
- Objective Lenses
- Stage
- Coarse Focus
22
Q
What is the highest practical magnification of a light microscope?
A
About 1000-1500.
23
Q
What is the resolution of a light microscope?
A
0.2 µm.
24
Q
What type of microscopy uses a beam of electrons?
A
Electron microscopy.
25
What is the maximum magnification of an electron microscope?
Up to 50 million times.
26
What is the main energy source for viewing in an electron microscope?
A beam of electrons.
27
What are some disadvantages of light microscope?
* Limited magnification
* Limited resolution
* Phototoxicity
* Photobleaching
28
What is the diameter of the field of view when looking through a microscope? Give the formula
Field Number (mm) / (Eyepiece Magnification x Objective Magnification)
29
What does the term 'organelles' refer to?
Internal structures of a cell with a particular function.
30
What is the function of the nucleus?
Control center of the cell, contains DNA.
31
What is the primary function of ribosomes?
Make proteins, enzymes, and hormones.
32
What do mitochondria produce?
Energy for the cell, known as ATP.
33
What is the function of the cell membrane?
Regulates what enters and leaves the cell.
34
What is the main difference between animal and plant cells?
* Animal: No cell wall, many lysosomes
* Plant: Cell wall, chloroplasts, large vacuoles
35
What is the function of the Golgi apparatus?
Modifies, sorts, and packages proteins.
36
What are mitochondria?
The cell's power sources, usually rod-shaped with a double membrane
37
What is the function of mitochondria?
Produces energy for the cell known as ATP through cellular respiration
38
What is the equation for cellular respiration?
Oxygen + Glucose → Carbon Dioxide + Water + ENERGY
39
What is the structure of Golgi bodies?
Stacks of membranes with many vesicles, sacs that transport chemicals
40
What is the primary function of Golgi bodies?
Prepare and store chemical products produced in the cell
41
What are the two types of Endoplasmic Reticulum?
* Rough ER
* Smooth ER
42
What is the function of Rough ER?
Protein synthesis, with ribosomes on its surface
43
What is the function of Smooth ER?
* Lipid synthesis
* Detoxification of harmful substances
44
What are lysosomes?
The cell's garbage disposal system containing enzymes
45
What is the function of lysosomes?
* Breakdown damaged organelles
* Recycle unwanted material
* Destroy foreign proteins
46
Where are centrioles located?
Near the nucleus in animal cells
47
What is the function of centrioles?
Spindle production in cell division
48
What is the cytoskeleton?
A network of tiny microtubules, microfilaments, and intermediate filaments
49
What is the function of the cytoskeleton?
* Provides support
* Maintains the cell's shape
* Assists in cell movement and transport of organelles
50
What are vacuoles?
Large sacs usually found in plant cells, containing cell sap
51
What is the function of vacuoles?
* Store water, nutrients, and enzymes
* Provide shape to plant cells
52
What is the cell wall made of?
Cellulose
53
What is the function of the cell wall?
* Provides support
* Prevents expansion of the cell
54
What are chloroplasts?
The food producers of plants, involved in photosynthesis
55
What is the equation for photosynthesis?
Carbon Dioxide + Water + Sunlight → Oxygen + Glucose
56
What is the function of the cell membrane?
Controls the exchange of material between the internal and external environments
57
What model describes the structure of the cell membrane?
Fluid mosaic model
58
What is the phospholipid bilayer?
Double layer of lipids that forms the cell membrane
59
What are integral proteins?
Proteins that span the membrane and are involved in transporting substances
60
What are peripheral proteins?
Proteins that sit on one of the surfaces of the membrane
61
What is the role of glycoproteins?
Involved in cell recognition and signaling
62
What is the role of cholesterol in the cell membrane?
Reduces fluidity and confers structural stability
63
What does passive transport require?
No energy
64
What is diffusion?
Movement of molecules from a region of higher concentration to a region of lower concentration
65
What is osmosis?
Diffusion of water molecules through a semipermeable membrane
66
Define hypotonic environment
Total concentration of solute outside the cell is less than inside the cell
67
Define hypertonic environment
Total concentration of solute outside the cell is greater than inside the cell
68
Define isotonic environment
Concentration of solute inside and outside the cell is equal
69
What happens to animal cells in a hypertonic solution?
Cells will shrink as water diffuses out
70
What are aquaporins?
Pores that allow water to move through the cell membrane by osmosis
71
What is facilitated diffusion?
Diffusion assisted by carrier or channel proteins
72
What are the key functions of membrane proteins?
* Junctions
* Enzyme activity
* Transport
* Recognition
* Anchorage
* Transduction
73
What defines the semi-permeability of the cell membrane?
Allows only certain molecules or ions to pass through
74
What factors affect the permeability of the cell membrane?
* Size of molecules
* Electrical charge
* Lipid solubility
75
What is the structure of phospholipids?
Consist of a polar head (hydrophilic) and two non-polar tails (hydrophobic)
76
What is the primary reason cells can function efficiently?
Water diffuses equally in both directions, resulting in no net movement of water into or out of the cell.
77
Why is freshwater hypertonic to freshwater fish?
The salt content in their body is higher than the salt content of the water surrounding them.
78
What adaptation do freshwater fish have to deal with the influx of water?
They urinate very frequently, producing high volumes of dilute urine.
79
What is the condition of seawater in relation to saltwater fish?
Seawater is hypertonic to the fish living in it.
80
How do saltwater fish compensate for water loss?
They drink huge amounts of water and excrete salt through their gills.
81
What prevents plant cells from bursting when placed in a hypotonic solution?
The cell wall prevents the cell from bursting.
82
What is the term used when plant cells are swollen due to water intake?
Turgid.
83
What is diffusion?
The movement of a molecule from high concentration to low concentration.
84
What is osmosis?
Diffusion of water molecules across a semi-permeable membrane from dilute to concentrated.
85
What is active transport?
The movement of molecules from a region of low concentration to a region of high concentration, requiring energy.
86
What type of molecules do transporter proteins carry during active transport?
Chemicals across the cell membrane.
87
Fill in the blank: Active transport utilises _______ for energy.
ATP.
88
What is endocytosis?
The process a cell takes in macromolecules by forming vesicles from the plasma membrane.
89
What are the two types of endocytosis?
* Pinocytosis (cell drinking) * Phagocytosis (cell eating)
90
What is exocytosis?
The process by which vesicles inside the cell fuse with the cell membrane and secrete their contents.
91
What factors affect the exchange of materials across membranes?
* Chemical properties
* Physical properties
* Concentration gradient
* Surface area-volume ratio
92
What are autotrophs?
Living things that can supply their own food, usually producers.
93
What process do most autotrophs use to make their own food?
Photosynthesis.
94
What are heterotrophs?
Organisms that depend on other organisms as sources of food.
95
What is photosynthesis?
The process by which plants utilise light energy to synthesise glucose from water and carbon dioxide.
96
What are the two phases of photosynthesis?
* Light-Dependent Stage
* Light-Independent Phase (Calvin cycle)
97
What is glycolysis?
The first stage in cellular respiration where glucose is split into two pyruvate molecules.
98
What are the products of aerobic respiration?
Carbon dioxide, water, and 38 ATP.
99
What is anaerobic respiration?
A type of respiration that occurs without oxygen.
100
What is the difference between alcoholic fermentation and lactic acid fermentation?
* Alcoholic fermentation produces ethanol and CO2
* Lactic acid fermentation produces lactic acid
101
What are enzymes?
Protein molecules that control all metabolic reactions in living cells.
102
What do catalysts do?
Accelerate chemical reactions without being changed at the end of the reaction.
103
What is the active site of an enzyme?
The surface of the enzyme where substrates temporarily bind.
104
What role do enzymes play in lowering activation energy?
They reduce the amount of activation energy required to start a reaction.
105
What is enzyme specificity?
Enzymes are highly specific and act on one substrate only.
106
What are enzymes?
Biological catalysts that increase the rate of chemical reactions without participating in the reaction itself
107
What would happen without enzymes?
Metabolism would be too slow to maintain life
108
What does specificity of enzymes mean?
Each enzyme acts on one substrate only
109
Why are enzymes specific in their action?
The shape of the active site of the enzyme matches the shape of the substrate molecule(s)
110
Define substrate in the context of enzymes
The molecules upon which the enzyme acts
111
What are products in enzyme reactions?
Substances formed as a result of the reaction that leave the enzyme surface
112
What is the Lock and Key Model?
A model suggesting that the substrate fits the enzyme active site like a key fits into a lock
113
What does the Lock and Key Model assume about the enzyme?
The enzyme has a rigid, unchangeable shape
114
What is the Induced Fit Model?
A model suggesting that the binding of the substrate causes a temporary change in the shape of the enzyme
115
What is the current accepted model of enzyme action?
The Induced Fit Model
116
How does temperature affect enzyme action?
Enzyme activity increases with temperature until an optimum is reached; high temperatures can denature enzymes
117
What happens to enzymes at high temperatures?
The chemical bonds maintaining the 3D shape are broken, altering the active site and decreasing activity
118
What is denaturation in the context of enzymes?
Permanent alteration of enzyme structure due to high temperatures
119
How does excessive cold affect enzyme activity?
Causes the enzyme to change shape and its functioning to slow down or stop, often reversible
120
What does pH refer to?
The acidity or alkalinity of a substance, measured by the concentration of hydrogen ions
121
What is the optimum pH for enzymes?
The specific pH at which each enzyme works best, usually within a narrow range
122
At what pH does pepsin work best?
pH 2, in the acidic environment of the stomach
123
At what pH does amylase work best?
pH 7, in the neutral environment of the mouth
124
What happens to the rate of reaction with increasing substrate concentration?
It increases until all active sites are occupied, then proceeds at maximum rate
