key terms - cells Flashcards
1
Q
Active transport
A
Movement of materials across membranes by using energy.
2
Q
endocytosis vs exocytosis
A
Endocytosis:
The process of a cell’s membrane stretching out around a large particle in order to engulf it.
Exocytosis:
The process of a cell ‘spitting out’ a large particle by fusing a vesicle with the cell membrane.
3
Q
What are the ‘pumps’ in active transport?
A
= ‘machinery’ that pumps a substance from an area of low concentration to an area of high concentration, against its concentration gradient.
4
Q
Cell
A
The basic building block of every living thing.
5
Q
DNA Replication
A
The process of creating a copy of every chromosome in the nucleus in preparation for mitosis.
6
Q
Double helix
A
The spiral shape of DNA
7
Q
Nucleotide
A
A group of a sugar, phosphate and a base.
8
Q
Complimentary base pairing
A
A pairs with T
C pairs with G
9
Q
Enzymes
A
Biological catalysts, which speed up the reactions inside cells.
10
Q
Active site
A
The ‘pocket’ in the surface of an enzyme where the substrate binds
11
Q
Substrate
A
The reactant catalysed by the enzyme
12
Q
Mitosis
A
The process of splitting one cell into two identical cells (cloning)
13
Q
Rate Limiting Factor
A
The reactant that is present in the smallest amount and therefore stops the rate of the reaction from increasing beyond a certain point.
14
Q
Organelles
A
The ‘machinery’ inside cells which enables them to carry out their life processes.
15
Q
Cell membrane
A
A phospholipid bilayer that surrounds a cell and determines what can get in and out of the cell
16
Q
Cell wall
A
A rigid structure that wraps around the outside of the cell membrane to give plant cells a rigid shape and structure.
17
Q
Chloroplasts
A
The organelle where photosynthesis is carried out (in plants).
18
Q
Chlorophyll
A
A pigment that traps sunlight.
19
Q
Grana
A
Stacks of thylakoids inside the stroma.
20
Q
Stroma
A
The liquid-filled space inside the inner membrane of chloroplasts.
21
Q
Thylakoids
A
Sacs covered with chlorophyll.
22
Q
Mitochondria
A
The organelle where respiration is carried out.
22
Q
Cytoplasm
A
The jelly-like, nutrient-rich substance that fills up cells.
23
Q
Cristae
A
The wiggly inner membrane of mitochondria (the wiggles increase surface area).
24
Intermembrane space
The space between the inner and outer membranes in mitochondria.
25
Matrix
The liquid-filled space inside the inner membrane of mitochondria.
26
Nucleus
The 'control centre' of the cell, containing the cell's DNA.
27
Passive transport
Movement of materials across cell membranes without the use of energy.
28
Diffusion
The movement of a substance from an area of high concentration toan area of low concentration, down its concentration gradient.
29
Osmosis
The movement of water from an area of low solute concentration to an area of high solute concentration.
30
Facilitated Diffusion
Diffusion of larger or charged molecules through channels inserted in the membranes of cells.
31
Solute
A substance that is dissolved in water.
32
Photosynthesis
The process of using light energy (from sunlight) to convert water and carbon dioxide into glucose for the plant to use as fuel to carry out its life processes.
33
Respiration
The process of reacting glucose with oxygen to produce ATP as energy for the cell, to enable it to carry out its life processes.
33
ATP
A form of energy that cells can use. The process of creating a copy of every chromosome in the nucleus in preparation for mitosis.
33
Light-dependent phase
- 1st stage of photosynthesis
(the splitting of water into hydrogen and oxygen).
34
Where does photosynthesis happen?
In the chloroplasts of plant cells.
35
Light-independent phase
- 2nd stage of photosynthesis
(the production of glucose from hydrogen and carbon dioxide).
36
equation for photosynthesis:
6CO2 + 6H2O ----> C6H1206 + 602
carbon dioxide + water ---> glucose + oxygen
37
What does 'photo' and 'synthesis' mean?
photo = light
synthesis = making
photosynthesis is making something using light.
38
Why do plants carry out photosynthesis?
Plants need sugar to be able to have the energy to carry out their life processes so that they can survive.
Plants get their food by making it themselves using photosynthesis.
39
What is produced from photosynthesis?
Glucose and oxygen is also produced as a waste product.
40
What needs to be present in order for photosynthesis to occur? Why?
Chlorophyll.
(found inside chloroplasts)
because it traps the sunlight which is needed for photosynthesis to occur.
41
What is needed for photosynthesis?
Carbon dioxide, water and sunlight
42
Word equation for photosynthesis:
Water + Carbon Dioxide + Light energy ---> Glucose + Oxygen
43
Balanced symbol equation for photosynthesis:
6H20 + 6C02 + Light energy ---> C6H1206 + 602
44
What are the two main stages of photosynthesis?
Light Dependent Phase
Light In-Dependent Phase
45
What does Light Dependent Phase mean? What happens?
Light is required in the Light Dependent Phase.
Sunlight hits the leaves of the plant, which are packed with chloroplasts. The chlorophyll then traps the sunlight.
Then, the light energy is used to split the water into hydrogen and oxygen.
46
What happens after the Light Dependent Phase?
Hint: What is the Calvin cycle?
The Calvin cycle uses the hydrogen and oxygen (products which result from H20 being split) to combine with carbon dioxide and create glucose.
47
Where does the Calvin cycle take place?
In the stroma outside of the thylakoids.
Thus, the light dependent phase takes place inside the thylakoids, and the light INdependent takes place in the stroma.
48
Which phase does the creation of glucose occur in?
Hint: photosynthesis
The creation of glucose is called the light-independent phase.
49
Why the light-independent reactions require sunlight, what time of the day would these reactions occur?
The light-independent reactions require sunlight because this is the phase which creates glucose. In order to create glucose, light is needed.
These reactions would therefore mostly occur when there is maximum sunlight, so during the daytime.
50
The result of the light-dependent phase of photosynthesis?
This results in split water, which becomes hydrogen and oxygen separated.
51
The result of the light-independent phase of photosynthesis?
This results in the creation of glucose.
52
What is the internal structure of the chloroplast?
There are two membranes: the inner and outer membrane.
Between these is the intermembrane space.
Within the inner membrane is the stroma, which is the dense fluid inside the chloroplast.
53
Which features of the chloroplast maximise the rate of photosynthesis?
The flat stacks of thylakoids (grana) have an increased area for the absorption of light, therefore it maximises the rate of photosynthesis (light energy is needed).
54
What is photosynthesis, and why is it used by plants?
Photosynthesis is the process of using light energy to make sugar out of carbon dioxide and water.
Plants need to undergo this process because they make their own food to survive, and the end result of photosynthesis is the creation of glucose (food).
This helps plants to carry out their essential life processes (MRS GREN).
55
How is the process of photosynthesis carried out in both the light-dependent and light-independent phases?
In the light-dependent phase, sunlight hits the leaves of the plant and is trapped by the chlorophyll, near the top of leaves (inside the chloroplasts). The light energy is then used to split water into hydrogen and oxygen. This phase takes place inside the thylakoids.
In the light-independent phase, the Calvin cycle combines the split water (oxygen and hydrogen) to create glucose. This takes place in the stroma.
56
Define Respiration
Respiration is the creation of energy.
57
What is needed for aerobic respiration? What are the starting reactants?
oxygen and glucose
58
What is produced by aerobic respiration?
ATP
+ carbon dioxide and water (waste products)
59
Define Aerobic Respiration
Aerobic Respiration is the process of reacting glucose with oxygen to produce ATP as energy for the cell, to enable it to carry out its life processes.
60
Equation for Aerobic Respiration
glucose + oxygen --> carbon dioxide + water + energy
61
When does anaerobic respiration occur?
When the amount of oxygen available can't keep up with the rate of aerobic respiration needed for ATP generation, during exercise or intense movement.
62
What is the product of anaerobic respiration in muscle cells?
lactic acid
63
What is anaerobic respiration AKA?
Fermentation
64
What are the wiggles called?
cristae
65
What are the features which maximise the rate of aerobic respiration in cells?
66
What is the purpose of aerobic respiration?
67
How is energy in the form of ATP produced in both aerobic and anaerobic respiration?
68
When would anaerobic respiration occur in the body and why?
69
How is surface area maximised inside the mitochondria, and what effect does this have on aerobic respiration?
70
What are the four stages of the cell cycle?
G1 phase
S phase
G2 phase
M phase
71
What happens in each of the four stages of the cell cycle?
G1 - cell grows, makes all of the machinery it needs for S phase
S - the DNA in the nucleus of the cell is replicated (so the cell gets two copies of everything)
G2 - again, the cell grows and makes all of the machinery it needs for M phase
M - this is mitosis, the process of splitting into two identical cells
72
Why does DNA need to be replicated?
The DNA must replicate before it divides. This is to ensure that each daughter cell successfully gets a copy of the instructions for genes and proteins.
73
What stage of the cell cycle is DNA replicated in?
S phase
74
Which direction are new nucleotides added to the new strand?
75
Why is DNA replication called semi-conservative?
76
How are the leading and lagging strand produced? Why are they replicated differently?
77
What is the purpose of mitosis?
for the growth and repair of cells
78
What steps are involved in mitosis?
79
How is mitosis carried out?
80
Where and when would you expect the rates of mitosis to be highest in humans and in plants?
