Structures and Functions in Living Organisms Flashcards
1
Q
What do most organisms have in common?
A
8 life processes
2
Q
What are the eight life processes?
A
nutrition excretion movement growth respiration response to stimuli reproduction controlling their internal enviroment
3
Q
What is nutrition?
A
needing nutrients to provide energy and raw materials for growth and repair
4
Q
Name 2 waste products (excretion)
A
carbon dioxide and urine
5
Q
What are all living organisms made up of?
A
cells
6
Q
What are the tiny structures inside a cell called?
A
organelles
7
Q
Name the organelles found in a typical animal cell
A
cell membrane
cytoplasm
nucleus
mitochondria
8
Q
Name the organelles found in a typical plant cell
A
cell membrane cytoplasm nucleus mitochondria cellulose cell wall permanent vacuole chloroplasts
9
Q
Similar cells are organised into….
A
tissues
10
Q
Tissues are organised into…
A
organs
11
Q
Organs make up…
A
organ systems
12
Q
How do cells release energy from food?
A
by respiring
aerobically and anaerobically
13
Q
How can substances move in and out of cells?
A
diffusion
osmosis
active transport
14
Q
What are the levels of organisation in an organism?
A
organelle cells tissues organs organ systems
15
Q
What is an enzyme?
A
A biological catalyst
16
Q
What do enzymes control?
A
All the reactions in a cell
17
Q
What does a catalyst do?
A
Speeds up a reaction without being used up or changing the reaction
18
Q
What are enzymes made of?
A
proteins (chains of amino acids)
19
Q
What is a substrate?
A
A molecule that is changed in a reaction
20
Q
What is an active sight?
A
A part of the enzyme where the substrate joins on to the enzyme
21
Q
What kind of model shows an enzyme working?
A
the ‘lock and key’ model
22
Q
When the substrate enters the active sight, what is it then called?
A
A substrate complex
23
Q
What two factors affect the rate of enzymes?
A
pH
temperature
24
Q
In an enzyme.. a higher temperature means..
A
an increased rate of reaction
25
What happens when the temperature of an enzyme is too hot?
Some of the bonds holding the enzymes together will break
This makes the enzyme lose its shape
The active sight no longer fits the substrate
The enzyme is DENATURED
26
What is the optimum temperature for human enzymes?
37 degrees
27
What is the process of cells breaking down small food molecules to release stored energy?
cellular respiration
28
What is the equation for aerobic respiration?
Glucose + Oxygen = Carbon Dioxide + Water (+ Energy)
| C6H12O6 + 6O2 = 6CO2 + 6H2O (+ Energy)
29
What do cells use aerobic respiration for?
Use oxygen to oxidise food
30
What is it called when cells have to respire with no oxygen?
anearobic respiration
31
When does anaerobic respiration take place?
In muscle cells when they are working hard during excersize
32
What is diffusion?
The net movement of particles from an area of high concentration to an area of low concentration
33
What are diffusion rates affected by?
concentration
temperature
available surface area
34
Where does diffusion happen?
In both liquids and gases
35
Diffusion is passive... What does this mean?
It takes place down a concentration gradient and does not use energy
36
What is Osmosis?
The net movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration
37
Name an example of a partially permeable membrane
A cell membrane
38
In osmosis there is a steady...
net flow
39
If a cell is short of water, the solution inside will become...
quite concentrated
40
Why does a cell short of water become concentrated?
So water can move into the cell by osmosis
41
If a cell has lots of water, the solution inside it will become...
more dilute
42
Are plants single celled or multi-cellular?
multi-cellular
43
What do plants store carbohydrate as?
Sucrose or starch
44
What are plant cell walls made up of?
cellulose
45
What do Animals store carbohydrate as?
Glycogen
46
What are vertebrates?
animals that have a backbone (vertebral column)
47
Name some invertibrates
sponges
molluscs
starfish
48
What do fungi feed off?
Other organisms
49
What are the two types of fungi?
Saprophytes
| Parasites
50
Are fungi multi-cellular?
Yes but some are single celled
51
What are fungal cell walls made out of?
chitin
52
What are multi-cellular fungi made up of?
A mycelium
53
What is a mycelium
a tangled network of thread-like structures called hyphae
54
What is saprotrphic nutrition?
Where FUNGI secrete extracellular enzymes into the area outside their body, to dissolve their food (so they can absorb their nutrients)
55
Many fungi act as...
decomposers
56
What do fungi store carbohydrate as?
glycogen
57
Name 2 examples of fungi
Yeast - single celled
| Mucor - multicellular
58
Can fungi photosynthesise?
no
59
Name two examples of protoctists
Chlorella (plant like)
| Amoeba (animal-cell-like)
60
Are protoctists multi-cellular or single celled?
single celled
61
Name two examples of bacteria
Lacto-bacillus bulgaricus
| Pneumococcus
62
Does bacteria cells have nuclei?
no
63
Can bacteria photosynthesise?
some can
64
What do bacteria feed off?
Other organisms
| both living or dead
65
What can lactobacillus bulgaricus be used for?
makes milk go sour and turn into yoghurt
66
Name the organelles in a bacteria cell
```
Cell Wall
Cytoplasm
Cell Membrane
Circular chromosome
plasmids
```
67
What are plasmids?
extra bits of DNA
68
Name two organelles of a virus particle
Protein coat
| DNA or RNA
69
Where so viruses reproduce?
inside living cells
70
What are organisms that depend on other organisms to live called?
parasites
71
Name two viruses and what they cause
1. Influenza virus
causes flu
2. HIV
causes AIDS
72
What does Tobacco mosaic virus do?
makes the leaves of tobacco plants discoloured by stopping them from producing chloroplasts
73
Name the bacteria that causes pneumonia
Pneumococcus
74
What protoctist causes malaria?
Plasmodium
75
What is Active Transport?
the movement of particles against a concentration gradient, using energy released during respiration
76
What three factors affect diffusion, osmosis, and active transport?
Surface Area to Volume Ratio
Temperature
Concentration Gradient
77
When cells have a larger surface area to volume ratio...
The rate of diffusion , osmosis and active transport is higher
78
What does concentration not affect?
active transport
79
pepsin is an enzyme working in the stomach. What is its optimum pH?
pH 2
| hydrochloric acid
80
what happens to the enzymes if the pH is too high/ too low?
the pH interferes with the bonds holding the enzyme together. This changes the shape of the active site and denatures the enzyme
81
what is the optimum pH for MOST enzymes?
neutral - pH 7
82
what is meant by the word 'turgid' to describe a plant cell?
when a plant is well watered, all its cells will draw water in by osmosis and become plump and swollen
83
what is the name for when, in a turgid cell, the contents of the cell start to push against the cell wall? why does this help the plant?
turgor pressure - helps support the plant tissues
84
what happens to plant cells if there's no water in the soil?
the plant starts to wilt because the cells start to lose water and so lose their turgor pressure - they become FLACCID
85
why, even when a cell is flaccid, does it not completely lose its shape?
the inelastic cell wall keeps things in position
