Topic 1 - Key Concepts In Biology Flashcards
What does a microscope do?
Makes small objects appear larger
What part of a microscope do you look through?
eyepiece lens
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 a building which is 828m tall?
same height: 828m
Order these in biggest-smallest: atom, animal cell, cell nucleus, muscle tissue, protein molecule, water molecule.
biggest: muscle tissue, animal cell, cell nucleus, protein molecule, water molecule, atom
A microscope has a x5 eyepiece lens and a x5 objective lens. What’s the total magnification?
5 x 5 = 25
A human hair has a width of 100 um but appears 20 mm wide in a photo. What’s the magnification in the photo?
200 x 20= 20,000
um:20,000 / 100 = 200
How many millimetres are there in a meter?
1000
What unit is 1000 times smaller then a mm?
micrometer, um
Nanometer symbol
nm
Whats an estimation?
an approximate value
Name one part you could find in a plant cell but not in an animal cell?
cell wall
chloroplasts
permanent vacuole
what process happens in mitochondrion
aerobic respiration
what is one function of a plant cell’s permanent vacuole?
keep the cell rigid
store substances
in which part of a plant cell is cell sap stored
vacuole
which part of a cell do you find the chromosomes
nucleus
when you look down a microscope, what is the area you see called?
field of view
why can an electron microscope detect smaller structures in cells than a light microscope?
it has a better magnification and better resolution
what is a picture taken with a microscope called?
micrograph
list 3 sub-cellular structures that are usually found in animal cells
cell membrane
nucleus
mitochondria
list three things found in plant cells but not in animal cells
vacuole, chloroplasts, cell wall
which cell structure controls what enters and leaves the cell?
cell membrane
which cell structure controls how the cell works
nucleus
which cell structure does respiration mainly take place?
mitochondria
which plant cell structure contains chlorophyll?
chloroplasts
what is the function of the structure that surrounds plant cells, but not animal cells
supports and protects the cell
whats the function of chlorophyll
capture light energy for photosynthesis
what is the function of ribosomes?
manufacture of proteins
what are gametes
sex cells
a bacterium is 20um long. How long is it in meters?
0.00002m
a bacterium is 5um wide. How wide is it in nanometers?
500nm
what part of an animal cell controls the cells activities?
nucleus
what do ribosomes make?
proteins
name one part that a plant cell might have but an animal cell would not have
chloroplast, vacuole, cell wall
what do bacteria use to move?
flagella
what word describes bacteria cells?
prokaryotic
name one structure that an animal cell would have but a bacteria cell wouldn’t what
nucleus, mitochondria
name substances that might be found in a cytoplasm of an egg cell to provide energy
fat, oil, lipid
in which system of the body is food broken down in
digestive system
why do we need to break down our food?
because the molecules in food are too large to cross cell membanes
in which organ of the body is digested food absorbed?
small intestine
which group of molecules help to digest food?
enzymes
examples of enzymes
amylase, protease, lipase
what does a sperm cell use for enzymes?
to digest a path through the jelly layer coat of the egg cell
do plant contain enzymes?
yes- they control many reactions inside plant cells
why are proteins and carbohydrates polymers?
they are made up of many similar molecules/monomers
which monomers make up starch?
glucose
which monomers make up a protein?
amino acids
what are enzyme carbohydrates?
proteins
what are fats and oils examples of
lipids
foods that contain starch?
potato, bread, rice, pasta
how does mitochondria provide energy?
break down molecules from food to release energy
what small molecules make up carbohydrates?
simple sugars e.g: glucose
what molecules form lipids
fatty acids and glycerol
what are subunits?
small molecules
which kind of large biological molecules are enzymes?
proteins
which subunits make up enzymes?
amino acids
where is amylase found?
mouth/salivary glands
found in small intestine/pancreas
whats a catalyst
molecule that speeds up rate of reaction
why are enzymes called biological catalysts?
they are molecules found inside living organisms that speed up the rate of reaction
what is a substrate?
a molecule that is changed in a reaction
what is the substrate for amylase?
starch
starch synthase is an enzyme that catalyses the synthesis of starch. what doe this mean?
the enzymes combines with all small sugar molecules and helps them join together to form starch
what are the subunits of enzymes?
amino acids
why do different enymes 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?
proteins
which kind of enzyme would beak down a food stain made by oil?
lipase?
what is the name of the part of an enzyme into which the substrate fits?
active site
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 enzymes will only work with particular substrates
what does denatured mean
an enzyme in which the active site has permanently changed shape
give two examples of changes in the cell environment that could cause the active site to change shape.
pH
temperature
which cell structure surrounds every kind of cell?
cell surface membrane
what is the function of the cell surface membrane?
control what enters and leaves the cell
name one gas that a cell needs to take in from its surroundings
oxygen needed for respiration
carbon dioxide needed for photosynthesis
name one other substance that a cell needs to take in from its surroundings
glucose/sugar 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 a high concentration to low
name a substance that is made inside a cell and leaves the cell
enzymes/hormones
what do plants take in from soil through their roots?
water & dissolved mineral salts
there is a 5% sucrose solution and a 10% sucrose solution. which is a higher concentration?
10% solution
two beakers contain the same volume of solution. One is a 10% sodium chloride solution, the other 5% sodium chloride solution. Which beaker contains more water molecules
5% solution
Independent variable
The variable that is changed during a science experiment
Dependent variable
The variable being tested or measured during a scientific experiment
Controll variable
A variable that is kept the same during a scientific experiment
What colour does iodine turn if starch is present
Blue/black
What is the function of Chromosomal dna
Controls cell activity and replication
What is the function of plasmid dna
Contain genes
Order of conversion
Nm
Lipase
Breaks down fats and glycerol
Test for lipase
Ethonal
Protease
Breaks down proteins to amino acids
Test for protease
Biruit solution (blue to purple)
