big to small Flashcards
what are the levels of organisation (smallest to biggest)
organelle -> cell -> tissue -> organ -> organ system -> organism
what is the definition of a cell
the smallest unit of an organism
e.g. glandular cells (animal)
palisade cell (plant)
what are tissues made up of
a group of cells with a similar structure and function, which all work together to do a particular job
e.g. stomach lining (animal)
leaf epithelium (plant)
what are organs made up of
a group of different tissues, which all work together to do a particular job
e.g. stomach (animal)
leaves (plant)
what is an organ system made up of
a group of different organs, which all work together to do a particular job
e.g. digestive system (animal)
photosynthetic system (plant)
what is an organism
an individual plant, animal, or single-celled organism
what is the role of the nucleus
contains genetic material, including DNA, which controls the cell’s activities
what is the role of the cell membrane
it controls the movement of substances in and out of the cell - made of a mixture of proteins and lipids (plants)
what is the role of the mitochondria
aerobic respiration occurs here, releases energy
what is the role of the chloroplast
light energy is absorbed and turned into food here (photosynthesis)
what is the role of the ribosomes
proteins are made here (protein synthesis)
what is the role of the cell wall
supports the cell and keeps its shape - made of cellulose (plant) chitin (fungi)
what is the role of the vacuole
full of cell sap and helps maintain cell shape
what is the role of the cytoplasm
where many chemical reactions take place
what does respiration mean
release of energy via glucose
what are the units of measurement (largest to smallest)
x1000 x1000 x1000 x1000
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km—> m—> mm—>μm—> nm
<——————————————
÷1000 ÷1000 ÷1000 ÷1000
what is the formula triangle for magnification
image size
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actual size x magnification
what are the 4 categories of biological molecules
carbohydrates, lipids, proteins and nucleic acids
what are the chemical elements in carbohydrate
CHO - carbon, hydrogen and oxygen
what are the chemical elements in lipid
CHO - carbon, hydrogen and oxygen
what are the chemical elements in protein
CHON - carbon, hydrogen, oxygen and nitrogen
name the chemical reaction which breaks down glucose to produce ATP
respiration
what is used to store glucose in plants
starch
what is used to store glucose in animals and fungi
glycogen
what are lipids (triglycerides) made of
fatty acids x3 joined to a glycerol molecule
what are 5 functions of lipids
•energy storage (can also be used in respiration)
•part of cell membranes
•thermal insulation
•electrical insulation - around nerve cells
•long term energy
•hormones
•buoyancy - helps marine animals such as wales to float
what are proteins made of
long chains of amino acids chemically bonded to each other
what are the monosaccharides of carbohydrates
•glucose
•fructose
•galactose
(single sugar)
what are the disaccharides of carbohydrates
•maltose
•sucrose
•lactose
(two sugar molecules linked)
what are the polysaccharides of carbohydrates
•starch
•glycogen
•cellulose
(many sugar molecules linked)
what are 5 functions in the body which protein is used in
•transport e.g. haemoglobin and cell membrane proteins (active transport)
•structural molecules e.g. collagen and keratin
•controls chemical reactions
•messenger molecules - hormones
•combating disease - antibodies
name two structural molecules which are made of protein
keratin and collagen
what are functions of carbohydrates
•fast energy source
•cellulose (cell wall)
•glycogen (animals)
•respiration (energy)
what are functions of proteins
•growth and repair
•antibodies (immune system)
•produces enzymes needed for digestion
•catalyse biological reaction
•hormones
what is the test for starch
chemical used - iodine solution
colour if starch is absent - yellow
colour if starch is present - blue/black
what is the test for glucose
chemical used - benedict’s solution
colour if glucose is absent - blue
colour if not much glucose is present - blue or green
colour if more glucose is present - yellow or brick red
(use brick red for if glucose is present though)
(only test that requires heat)
what is the test for protein
chemical used - biuret solution
colour if protein is absent - blue
colour if protein is present - purple
what is the test for lipid
chemical used - ethanol (shake), water (shake)/emulsion test
colour if lipid is absent - clear
colour if lipid is present - milky white
which molecules are insoluble in water
starch, cellulose, lipids
what are the chemical elements in glucose
CHO - carbon (6), hydrogen (12) and oxygen (6)
what is the structure of DNA
two strands (sugar phosphate backbone) coiled to form a double helix, the strands being linked by a series of pair basis: adenine (A) with thymine (T), and cytosine (C) with guanine (G)
(way to remember – apple in tree, car in garage)
what are the sex chromosomes of a female
XX
what are the sex chromosomes of a male
XY
what is a nucleotide made of
sugar + phosphate + base = nucleotide
what are the small circles on the edge of a DNA structure called
phosphate
what are the pentagon shapes on the edge of a DNA structure called
sugar
how are DNA and nucleotides related
DNA (and RNA) are polymers of nucleotides
how are bases in DNA connected
pairs of bases are chemically bonded together by hydrogen bonds (complementary base pairing)
where is DNA stored
in the nucleus (holds the genetic material)
what are chromosomes
the DNA forms a number of structures called chromosomes, in the structures DNA is coiled around proteins called histones, this allows lots of DNA to be packed into a single cell
(they look like Xs), humans have 23 (in gametes)pairs of chromosomes (46 chromosomes in total)
what is a gene
a gene is a section of DNA, which codes for a specific protein (-main answer), these proteins control the individual’s characteristics, many genes are found on each chromosome
what is a genome
the entire set of genes of an organism
what is an allele
an alternative form of a gene
what is DNA
deoxyribonucleic acid - the genetic material in all organisms (except some viruses)
what is double helix
the shape of the DNA molecule
what is a polymer
a long chain of many repeating monomers
what are nucleotides
the single units (monomers) that join together to form the DNA strand
what are the chemical elements in DNA
CHONP - carbon, hydrogen, oxygen, nitrogen, and phosphorus
what is a monomer of DNA
nucleotides
what is a polymer of DNA
nucleic acid
what enzyme breaks down starch into maltose
amylase
what are enzymes
•biological catalysts
•a chain of amino acids, which is folded, produces a unique 3D structure (enzymes = protein)
what is the lock and key theory
Enzymes and substrates randomly move around, due to their kinetic energy, until they eventually collide, the active site (the lock) will have a specific shape that can only bind to a specific substrate (the key) (enzyme specificity) in order to react. The substrate binds to the active site forming an enzyme substrate complex, the reaction occurs converting the substrate into the product e.g. starch —> maltose, once the product is formed it detaches from the enzyme and diffuses away.
observations of catalase
can see bubbles of oxygen - allows us to see the rate of reaction
2H₂O —> 2H₂O + O₂
describe and explain the potato enzyme practical
enzymes are biological catalysts, they speed up reactions by lowering the activation energy. The substrate will bind to an enzyme’s active site, this forms an enzyme substrate complex. Catalase is an example of an enzyme found in potatoes, catalase breaks down hydrogen peroxide into oxygen and water, bubbles can be observed. The more bubbles, the faster the reaction if catalase gets too hot. It will denature and the active site will change shape. This means the substrate will no longer be able to bind with the active site. Potato is cut up into chunks, the surface area is increased meaning the enzyme reaction is faster as more enzyme is available to react with the substrate.
describe denaturation
if enzymes are exposed to extremes of pH or high temperatures the shape of their active site may change, this means that an enzyme substrate complex cannot be formed as the substrate will no longer fit, and the rate of reaction will decrease quickly
what are the eukaryotic organisms
plants, animals, fungi, protoctista
animal cell knowledge
• multicellular
• no cell walls
• store carbohydrate as glycogen
• cannot photosynthesise
• able to move from one place to another
• usually have nervous coordination
• most feed off other organisms
plant cell knowledge
• multicellular
• have cell wall made of cellulose (type of carbohydrate)
• contain chloroplast so can photosynthesise
• store carbohydrates as starch
fungi cell knowledge
• usually multicellular
• stores carbohydrate as glycogen
• cell walls made of chitin
• cannot photosynthesise - chloroplast
• feed by extracellular secretion of digestive enzymes (saprotrophic nutrition)
• filaments called hyphae bunch together to form mycelium
protoctista cell knowledge
• amoeba (similar to animal cells)
• plasmodium (causes malaria)
• chlorella (has chloroplasts)
• unicellular
• different species use starch or glycogen for storage
• have mitochondria
define heterotrophic
eat another organism – animals
define autotrophic
make food through photosynthesis (CO₂ + water = glucose + oxygen)
define saprotrophic
extracellular enzymes
prokaryote examples
lactobacillus and pneumococcus
what is a bacterial cell wall made of
murein
how is a bacterial chromosome different to the chromosomes in an animal cell
circular
bacteria are prokaryotic organisms, what is the distinguishing feature of a prokaryotic cell
no membrane bound organelles and have circular DNA
describe two ways that bacteria obtain nutrients
performing photosynthesis or breaking down chemical compounds
what is a pathogen
an organism that has the ability to cause disease (fungi, protoctista, prokaryotes (bacteria))
what are viruses composed of
nucleic acid, protein, lipids, and carbohydrates
describe viral reproduction
hijack cell’s machinery to make proteins and parts of themselves, they replicate inside the cell, which can lead to the cell membrane of the host cell to burst/rupture/lyse and the released viruses repeat the process again
(there are two types of viral reproduction; the lytic cycle and the lysogenic cycle (longer word - longer process))
are viruses alive
no can’t reproduce (on their own) or respire, they are not prokaryotes or eukaryotes and are much smaller than cells
what does the term activation energy mean
the minimum amount of energy particles must have to be able to react
what is the best explanation of the term ‘denature’
an irreversible change of the active site of an enzyme
what are the monomers called which are joined together to make an enzyme
amino acids
what are specialised cells
cells that will have special features that allow the cell to do it’s job
what are undifferentiated cells capable of
•undifferentiated cells that have the ability to become specialised •capable of self renewal
•capable of differentiation
•they can become any type of cell
define embryonic stem cells
cells found in embryo and can differentiate into any type of cell
define adult stem cells
cells found in bone marrow and can differentiate into a limited number of types of cell
what is the difference between structure and function of a cell
structure - the features of a cell
function - the job/role of a cell
what is the role and adaptation of a palisade cell
role - photosynthesis
adaptation - lots of chloroplast
what is the role and adaptation of a cilia cell
role - wafting pathogens out of the body
adaptation - hairs (extensions of the cell membrane)
what is the role and adaptation of a nerve cell
role - transmit messages
adaptation - very long and branched
what is the role and adaptation of a root hair cell
role - absorb water and minerals from soil
adaptation - thin membranes
why do sperm cells need many mitochondria
sperm cells need a lot of energy to swim
do ribosomes produce enzymes
an enzyme is a protein and protein synthesis occurs in the ribosomes of cells, particularly cells that have the role of producing enzymes for the digestion of material in the small intestines, so one adaptation would be that it has many ribosomes
