GCSE Biology Revision "Sizes of Cells"
Summary
TLDRIn this educational video from Freez lessons, viewers are introduced to the concept of measuring cell sizes using scientific units. The video explains the use of metric prefixes such as centi, milli, micro, and nano to describe sizes in biology, which are often smaller than everyday objects. It covers the conversion from meters to centimeters, millimeters, micrometers, and nanometers, highlighting their applications in describing the dimensions of cells and cellular components. The video emphasizes the practicality of these units, especially in the context of cell biology, and encourages practice with the provided workbook.
Takeaways
- 🔬 The video discusses the sizes of cells and introduces scientific prefixes to describe them.
- 🐕 A German shepherd's average length is used as a reference point, being about 1 meter.
- 📏 The prefix 'centi' means 100th, and 1 centimeter (cm) is 1/100th of a meter or 1 × 10^-2 meters.
- 🖊️ The width of a little finger is approximately 1 cm, and the tip of a ballpoint pen is about 1 mm.
- 🔢 The prefix 'milli' means 1,000th, and 1 millimeter (mm) is 1/1,000th of a meter or 1 × 10^-3 meters.
- 🐕🦺 In biological terms, 1 millimeter is quite large, as a dog is 1,000 mm long, which is 1 meter.
- 🔬 Scientists use even smaller units like micrometers for cell sizes, with the prefix 'micro' meaning 1 millionth.
- 🌌 A micrometer (μm) is 1 × 10^-6 meters, and typical human cells range from 10 to 20 micrometers in size.
- 🔍 The prefix 'nano' means one billionth, and 1 nanometer (nm) is 1 × 10^-9 meters, used to measure very small biological structures like proteins.
- 📚 The video encourages practice with the provided vision workbook for questions on cell sizes.
Q & A
What is the main focus of the video from Freez lessons?
-The main focus of the video is to teach viewers how to describe the size of cells and how to use the prefixes centi, milli, micro, and nano.
Why might the material in the video seem tricky to some viewers?
-The material might seem tricky because it involves understanding the size of cells and the use of scientific prefixes, which could require multiple viewings to grasp.
What is the difference between eukaryotic and prokaryotic cells in terms of size as mentioned in the video?
-Prokaryotic cells are much smaller than eukaryotic cells.
What is the average length of a German shepherd mentioned in the video, and how is it measured?
-The average length of a German shepherd is around 1 meter (M).
What does the prefix 'centi' mean and what is its symbol in standard form?
-The prefix 'centi' means 100th, and in standard form, it is represented as 1 * 10^-2 m.
How is the width of a little finger related to centimeters?
-The width of a little finger is around 1 centimeter (cm).
What does the prefix 'milli' mean and what is its symbol in standard form?
-The prefix 'milli' means 1,000th, and in standard form, it is represented as 1 * 10^-3 m.
What is the approximate size of a typical human cell in micrometers?
-A typical human cell is around 10 to 20 micrometers in size.
What does the prefix 'nano' mean and what is its symbol in standard form?
-The prefix 'nano' means one billionth, and in standard form, it is represented as 1 * 10^-9 m.
Why are nanometers a useful unit for biologists?
-Nanometers are a useful unit for biologists because they allow for the measurement of very small objects such as proteins and other cellular components.
What is the approximate diameter of a molecule of hemoglobin in nanometers?
-A molecule of hemoglobin is around 5 nanometers in diameter.
Outlines
🔬 Introduction to Cell Sizes and Measurement Prefixes
This paragraph introduces the topic of cell sizes and the importance of understanding various measurement prefixes. The video aims to teach viewers how to describe the size of cells using the prefixes 'centi', 'milli', 'micro', and 'nano'. It highlights the difference in size between prokaryotic and eukaryotic cells, with the former being significantly smaller. The script explains that scientific measurements are based on the meter but often require smaller units for biological objects. It provides examples of converting meters to centimeters and millimeters, and then introduces the micrometer and nanometer as units for measuring smaller biological entities like cells and their components. The paragraph concludes with a mention of the usefulness of these units in biology and hints at future topics, such as the size of ribosomes.
Mindmap
Keywords
💡Eukaryotic cells
💡Prokaryotic cells
💡Meter
💡Centimeter
💡Millimeter
💡Micrometer
💡Nanometer
💡Standard Form
💡Prefixes
💡Hemoglobin
💡Ribosomes
Highlights
Introduction to describing the size of cells using scientific prefixes.
Explanation of the difficulty in grasping the size of cells due to their small size.
Comparison of the size differences between eukaryotic and prokaryotic cells.
Definition and use of the metric system's base unit, the meter, in biological contexts.
Introduction to the prefix 'centi' meaning 100th, and its relation to the centimeter.
Conversion of centimeters to meters using standard form notation.
Description of the size of a German shepherd dog to illustrate the concept of a meter.
Introduction to the prefix 'milli' meaning 1,000th, and its relation to the millimeter.
Conversion of millimeters to meters using standard form notation.
Example of the size of a ballpoint pen tip to illustrate the concept of a millimeter.
Introduction to the prefix 'micro' meaning one millionth, and its relation to the micrometer.
Conversion of micrometers to meters using standard form notation.
Description of the typical size of a human cell using micrometers.
Introduction to the prefix 'nano' meaning one billionth, and its relation to the nanometer.
Conversion of nanometers to meters using standard form notation.
Explanation of the importance of nanometers in measuring proteins and cells.
Example of the size of a hemoglobin molecule in nanometers.
Encouragement to practice describing cell sizes using the learned prefixes.
Transcripts
[Music]
hi and welcome back to Freez lessons.
co.uk by the end of this video you
should be able to describe the size of
cells you should then be able to use the
prefixes CTI Millie micro and
Nano now I should point out that this
material may seem quite tricky you might
need to watch this video a couple of
times to get the
ideas in the last video we started
looking at cells we looked at the
similarities and differences between
eukariotic cells such as animal and
plant cells and procaryotic cells such
as
bacteria one of the key differences is
that procaryotic cells are much smaller
than eukariotic cells in this video
we're going to look at the sizes of
cells so let's get started all sizes in
science are based on the meter but the
problem is that objects in biology are
often much smaller than that let's look
at some
examples I'm sure sh you here a German
shepherd and the average length of a dog
like this is around 1 M now if we divide
1 M into 100 equal parts then we've got
1
cm the word CTI means 100th so 1 cenm is
100 of a meter now scientists often use
standard form and you could be expected
to use that in your exams 1 cm is 1 * 10
^ of - 2
m just to give you an idea of the size
of that the width of your little finger
is around 1
cm now again in biology 1 cm is large if
we divide 1 cm into 10 equal parts then
we've got 1 mm so 1 cm is 10
mm again just to give you an idea of
that the tip of a ballpoint pen is
around 1
mm now the word Millie means 1,000th so
1 mm means 1,000th of a meter and again
using Standard Form 1 mm is 1 * 10^ of -
3
m going back to the dog we can see that
this is 1,000 mm long in other words 1
M now again in biology 1 millim is
pretty big so scientists work with even
smaller
sizes if we take a meter and divide this
into 1 million equal parts then we've
got a
micrometer the word micro means 1
millionth so one micrometer is 1
millionth of a meter a micrometer has
this symbol and I'd recommend that you
learn
that in standard form 1 micrometer is 1
* 10 the^ of - 6
M now a typical human cell such as this
one is around 10 to 20 micrometers in
size that means that biologists find a
micrometer a very useful unit especially
when looking at
cells now cells contain small Parts such
as ribosomes and we're going to look at
those in a later video this means that
we need an even smaller unit to talk
about the sizes of objects inside
cells so the final unit we're going to
look at is called the
nanometer the word Nano means one
billionth so 1 nanometer is 1 billionth
of a meter in standard form a nanometer
is 1 * 10 ^ of - 9 M now I should point
out that a nanometer is a very small
size Pro proteins and cells are measured
using nanometers this shows the protein
hemoglobin which is found in red blood
cells a molecule of hemoglobin is around
5 nanometers in
diameter remember you'll find plenty of
questions on the size of cells in my
vision workbook which you can get by
clicking on the link above okay so
hopefully now you should be able to
describe the size of cells you should
then be able to use the prefixes CTI
Millie micro and
Nano
[Music]
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