Topic 1 - Key Concepts in Biology Flashcards

1
Q

What are all living things made up of?

A

Cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the two types of cell?

A
  • Eukaryotic (Complex, animal and plant cells)

- Prokaryotic (Simple, bacteria)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a prokaryote?

A

A single-celled organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What do both animal and plant cells contain?

A
  • Nucleus
  • Cytoplasm
  • Cell membrane
  • Mitochondria
  • Ribosomes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What extra subcellular structures do plant cells contain?

A
  • Cell wall
  • Vacuole
  • Chloroplasts
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the main structure that a bacterial cell does not contain?

A

Nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a specialised cell?

A

A cell with a specialised purpose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Name three specialised cells, and give reasoning:

A
  • Sperm Cell: Many mitochondria to swim, enzyme in head, has a flagellum
  • Egg Cell: Nutrients in cytoplasm
  • Ciliated Epithelial Cell: Have cilia on the ends
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What apparatus do we use to study cells?

A

Microscopes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the most powerful microscope, and what is its magnification power?

A

Electron microscope - 2000000x

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the equation for total magnification?

A

Total magnification = Eyepiece lens magnification x Objective lens magnification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the equation for magnification if you don’t know the lens magnifications?

A

Magnification = Image size / Real size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is an enzyme?

A

A catalyst produced by living things

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why does an enzyme only catalyse one reaction?

A

Because the active site is of a shape that only fits a particular substrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What 3 factors affect enzyme-catalysed rates of reaction, and why?

A
  • Temperature: High temp. causes denaturing
  • pH: Low and high pH cause enzymes to denature
  • Substrate conc.: More substrates means more active sites are filled
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What break down big molecules such as carbohydrates, proteins and lipids?

17
Q

Name the three conversions of big molecules, including the enzyme used:

A

Starch + Amylase = Maltose
Protein + Protease = Amino Acids
Lipid + Lipase = Glycerol and fatty acids

18
Q

What is the test for sugars?

A
  • Add Benedict’s reagent (blue) to a sample
  • Heat to 75 degrees Celsius
  • If the test is positive, a precipitate either yellow, orange or red in colour will form
19
Q

What is the test for starch?

A
  • Add iodine to the test sample

- If the test is positive, the sample changes from browny-orange to blue-black.

20
Q

What is the test for lipids?

A
  • Add ethanol to the test substance and shake
  • When it dissolves, add it to water
  • If the test is positive, a milky coloured precipitate will rise above the water
21
Q

What is the test for proteins?

A
  • Add potassium hydroxide to the solution
  • Add copper II sulfate (blue)
  • If the test is positive, the colour will change from blue to purple
22
Q

How do you test the number of calories in a food?

A

Calorimetry

23
Q

What are the steps for carrying out a calorimetry?

A
  • Weigh the sample
  • Measure a set volume of water
  • Measure the temperature
  • Heat the sample until it burns
  • Hold the burning food under the water
  • Measure the change in temperature
24
Q

How do you calculate the energy in food (J)?

A

Energy in food = Mass of water x Temperature change x 4.2

25
How do you calculate energy per gram of food?
Energy per gram of food = Energy in food / Mass of food
26
What are the three ways substances can move?
- Diffusion - Osmosis - Active Transport
27
Define diffusion:
The net movement of particles from an area of high concentration to low concentration.
28
Define osmosis:
The net movement of water molecules across a partially permeable membrane from an area of high concentration to low concentration.
29
Define active transport:
The net movement of particles across a membrane AGAINST the concentration gradient. It is the only transportation method that requires energy to take place.
30
What are the steps in an experiment to investigate osmosis?
- Prepare sucrose solutions of different concentrations - Cut a potato into equal size and weight pieces - Put the potato pieces into the sucrose solutions (e piece per solution) - Wait for at least 40 mins - Re-weigh the potatoes
31
What does the graph for the osmosis practical look like? Describe what each section shows:
It is a curve moving down and right - Above x-axis = Higher conc in solution than potato - On x-axis = Concentrations are equal - Below x-axis = Higher conc in potato than soution