Flashcards in Topic 1 - Key Concepts in Biology Deck (87):
What does a microscope do?
Makes small objects appear larger/magnifies small objects
What part of a microscope do you look through?
Which part of a microscope do you use to get a clear image?
the focusing wheel
If an average height person in Year 10 is magnified 600 times, how tall will they be compared to the tallest building in the world, which is 828 m tall?
about the same height; the Burj Khalifa, Dubai is 828 m tall
Put these in order of size, biggest first: atom, animal cell, cell nucleus, muscle tissue, protein molecule, water molecule
muscle tissue, animal cell, cell nucleus, protein molecule, water molecule, atom
A microscope has a ×5 eyepiece lens and a ×5 objective lens. What is the total magnification?
×25; 5 × 5 = 25
A human hair has a width of 100 μm but appears 20 mm wide in a photo. What magnification is the photo?
×200; 20 mm = 20 000 μm; 20 000 ÷ 100 = 200
How many millimetres are there in a metre?
What unit is 1000 times smaller than a millimetre?
What is the unit symbol for a nanometre?
What is an estimation?
an approximate value
Name one part you could find in a plant cell but not an animal cell.
cell wall, chloroplasts, permanent vacuole
What process happens in a mitochondrion?
What is one function of a plant cell’s permanent vacuole?
to help keep the cell rigid/to store substances
In which part of a plant cell is cell sap stored?
In which part of a cell would you find chromosomes?
When you look down a microscope, what is the area that you see called?
field of view
Why can an electron microscope detect smaller structures in cells than a light microscope?
it has better magnification and better resolution
What is a picture taken with a microscope called?
Some microscope pictures have a small line drawn on them with information about how long the line is when unmagnified. What is this line called?
List three sub-cellular structures that are usually found in animal cells.
any three from: cell membrane, nucleus, mitochondria,
List three sub-cellular structures found in plant cells but not in animal cells.
large permanent vacuole, chloroplasts, cell wall
Which cell structure controls what enters and leaves the cell?
Which cell structure controls how the cell works?
In which cell structure does respiration mainly take place?
Which plant cell structure contains chlorophyll?
What is the function of the cell structure that contains chlorophyll?
to capture energy from light for photosynthesis/to produce glucose using photosynthesis
Describe the function of the structure that surrounds plant cells, but not animal cells.
supports and protects the cell
What is the function of ribosomes?
manufacture of proteins
What are gametes?
A bacterium is 20 μm long. How long is it in metres?
A bacterium is 5 μm wide. How wide is it in nanometres?
What part of an animal cell controls the cell’s activities?
What do ribosomes make?
Name one part that a plant cell might have but an animal cell would not.
chloroplast, permanent large vacuole, cell wall
What do bacteria use to move themselves?
Animal and plant cells are eukaryotic. What word describes bacterial cells?
Name one structure that an animal cell would have but a bacterial cell would not.
What is this format for numbers called: A × 10n?
What is 1 × 106 m written as an ordinary number?
1 000 000 m
Name two substances that might be found in the cytoplasm of an egg cell to provide energy.
carbohydrate or starch, lipid or fat or oil
Egg cells also contain protein. Which cell structure makes proteins?
In which system of the body is food broken down?
Why do we need to break food down?
because the molecules in food are too large to cross cell membranes
In which organ of the body is digested food absorbed?
Which group of molecules help to digest food?
Give one example of the group of molecules that you named in the previous question.
any suitable example, such as amylase, protease, lipase
What does a sperm cell use enzymes for?
to digest a path through the jelly coat of the egg cell
Do plants contain enzymes?
yes – they control many reactions inside plant cells
anywhere a reaction takes place
Why are proteins and carbohydrates examples of polymers?
They are made up of many similar molecules/monomers.
Which monomers make up starch?
Which monomers make up a protein?
Are enzymes carbohydrates, proteins or lipids?
Which group of substances are fats and oils examples of?
Name one food that contains a lot of starch.
any suitable example such as: potato, pasta, bread, rice
What effect does the enzyme amylase have on starch?
breaks it down to small sugars/maltose
Food provides nutrients for growth. What else is it a source of, which we need for activity?
Which cell structures break down molecules from food to release energy?
What are the subunits (small molecules) that make up carbohydrates?
simple sugars, e.g. glucose
Which two kinds of subunits form lipids (fats and oils)?
fatty acids and glycerol
Which kind of large biological molecule are enzymes?
Which subunits make up enzymes?
Amylase is a kind of enzyme. Where is it found in humans?
mouth/salivary glands and small intestine/pancreas
What is a catalyst?
A molecule that speeds up the rate of a reaction
Why are enzymes called biological catalysts?
They are molecules found inside living organisms that speed up the rate of reactions.
What is a substrate?
A molecule that is changed in a reaction
What is the substrate for amylase?
Starch synthase is an enzyme that catalyses the synthesis of starch. Explain what this means.
The enzyme combines with subunits/small sugar molecules and helps them join together to form starch.
What are the subunits of enzymes?
Why do different enzymes have different 3D shapes?
The amino acids are arranged in a different order in different proteins.
Which kind of large organic molecule does a protease digest?
Which kind of enzyme would break down a food stain made by sunflower oil?
What is the name of the part of an enzyme into which the substrate fits?
Why do most enzymes only work with one substrate?
Only substrates with the same shape as the active site can sit in the site and take part in the reaction.
Enzymes are specific to their substrate. What does this mean?
The enzyme will only work with particular substrates – those substrates that have the right shape.
Which term describes an enzyme in which the active site has permanently changed shape?
What effect does a large change of shape of an enzyme's active site have on how the enzyme works?
The enzyme no longer works.
Give two examples of changes in the cell environment that could cause the active site to change shape.
Which cell structure surrounds every kind of cell?
cell surface membrane
What is the function of this cell structure?
to control what enters and leaves the cell
Name one gas that a cell needs to take in from its surroundings, and explain your answer.
oxygen needed for respiration/to release energy in mitochondria; carbon dioxide needed for photosynthesis
Name one other substance that a cell needs to take in from its surroundings, and explain your answer.
any suitable answer, such as glucose/sugar needed for respiration
Carbon dioxide is produced inside a cell and moves out of the cell by diffusion. What does this mean?
there is an overall movement of gas particles from where there are more of them to where there are fewer
Name one other substance that is made inside a cell and leaves the cell.
any suitable substance, such as enzymes or hormones that are secreted
Name two substances that plants take in from the soil through their roots.
water and dissolved mineral salts
There is a 5% sucrose solution and a 10% sucrose solution. Which solution has the higher concentration of sucrose?