Flashcards in Biology - Topic 1 - Key Concepts in Biology Deck (70):
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
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?
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 usuallyfound in animal cells.
cell membrane, nucleus, mitochondria, ribosomes
Which cell structure controls what enters and leaves the cell?
Which cell structure controls how the cell works?
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 cell wall
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 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 1 × 10^6m 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
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?
Name an example of an enzyme
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
Name a part of a plant where you might findenzymes.
anywhere a reaction takes place, e.g. in chloroplasts for photosynthesis, in mitochondria for respiration, where starch grains are made
What nutrient is starch an example of?
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.
potato, pasta, bread, rice
What effect does the enzyme amylase have on starch?
breaks it down to small sugars
Food provides nutrients for growth. What else is it a source of, which we need for activity?
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 subunits make up enzymes?
Amylase is a kind of enzyme. Where is it found?
mouth/salivary glands and small intestine/pancreas
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.
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?
What is the name of the part of an enzyme into which the substrate fits?
Why do most enzymes only work with onesubstrate?
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 doesthis 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.
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 fromwhere there are more of them to where there are fewer
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?