3rd Form Definition and Key Concepts Flashcards
cell
the basic building block of all living organisms that are made up of organelles
eukaryotic cell
a type of cell found in animal, plant, fungi and protoctist cells that contain a nucleus
animals
a kingdom where all organisms are multicellular, do not photosynthesize, no cell walls and store their carbohydrates as glycogen
plants
multicellular, cells do contain chloroplasts, do photosynthesize, do contain cell walls and store carbohydrates as starch
fungi
no photosynthesis, feed via saprotrophic nutrition, composed of mycelium which consists of many hyphae, can be both multi and unicellular (yeast), contain cell walls and store carbohydrates as glycogen
protoctists
microscopic, single celled organisms
prokaryotic cell
a cell found in the bacteria kingdom that does not contain a nucleus
bacteria
single celled, prokaryotic (no nucleus) organisms, contain a cell wall and plasmids
virus
a non-living organism that can only reproduce inside host cells (parasitic). they
have no cells and contain a protein coat and nucleic acids (DNA or RNA)
unicellular
an organism made up of a single cell (bacteria and protoctista)
amoeba
protoctists that live in pond water and resemble animal cells with
chloroplasts
chlorella
a protoctist that has features similar to plant cells, e.g. chloroplasts
chloroplast
an organelle that is the site of photosynthesis
DNA
a double stranded molecule made of nucleotides, wound in a double helix shape, carrying the genetic code
human immunodeficiency virus (HIV)
a virus that weakens the immune system and can lead to acquired immunodeficiency syndrome (AIDS)
influenza
an infectious virus that causes the flu
hyphae
long filaments of a fungus that contain many nuclei
lactobacillus bulgaricus
a rod-shaped bacteria, used to produce yoghurt from milk
MRS H GREN
the characteristics an organism must have to be classed as living;
Movement, Respiration, Sensitivity (to their environment), Homeostasis, Growth,
Reproduction, Excretion and Nutrition
mucor
a multicellular fungus that has many hyphae
multicellular
refers to an organism that is made up of more than one cell. these
organisms are only found in animals, plants and some fungi
mycelium
a collection of thread-like hyphae in fungus
pathogens
microorganisms that cause disease to its host that can include bacteria,
protoctists, fungi and viruses
photosynthesis
a reaction where energy is transferred from the environment to the chloroplasts by light to produce glucose
plasmids
loops of DNA found in the cytoplasm of prokaryotic cells
plasmodium
pathogenic protoctists that cause malaria
pneumococcus
a spherical, pathogenic bacteria that causes pneumonia
saprotrophic nutrition
the mode of extracellular nutrition in which digestive enzymes are secreted onto food outside of the cell and the products of digestion are absorbed
yeast
a single celled fungus
tobacco mosaic virus (TMV)
a plant pathogen which produces a mosaic pattern on the leaves, infecting chloroplasts and limits plant growth
organelle
a specialised structure found inside of cells, e.g. a nucleus
cell
the basic building blocks of all living organisms
tissue
a collection of cells with similar structure and function
organs
collection of tissues performing specific functions
organ system
group of organs that work together to form organisms
cell differentiation
the process where cells become specialised by producing
different proteins
cell membrane
a partially permeable barrier that surrounds the cell (allows some
substances to move in and out of the cell)
cell wall
a fully permeable outer layer found in some cells. In plants it is made from cellulose and in fungi, chitin
chloroplast
an organelle that is the site of photosynthesis
cytoplasm
contains dissolved nutrients and all of the organelles of the cell and the
site of many metabolic reactions
mitochondria
an organelle that is the site of aerobic respiration
nucleus
an organelle found only in eukaryotic cells and contains the genetic material (DNA) and controls the activities of the cell
ribosomes
organelles that are the site of protein synthesis
stem cells
undifferentiated cell that can divide rapidly to produce specialised cells
vacuole
found in plant cells, contains dissolved nutrients and supports the shape of the cell
lipids
a group of molecules including fats and oils, made from fatty acid chains and glycerol containing the elements carbon, hydrogen and oxygen. can test for them
using the emulsion test
proteins
large polymers made from amino acids, containing the elements carbon, hydrogen, oxygen, nitrogen and occasionally other elements like sulphur, involved in
repairing and the growth of cells. can test for them using the biuret test
amino acids
the monomer from which proteins are assembled from
starch
a carbohydrate made from glucose monomers, containing the elements carbon, oxygen and hydrogen and acts as an energy store in plants. can test for starch
using iodine
glycogen
a carbohydrate made from glucose that acts as an energy store in animals
enzymes
proteins that are biological catalysts that increase the rate of reactions by providing an alternative pathway with a lower activation energy
active site
part of the enzyme that is complementary to the shape of the substrate which can change shape if the enzyme is exposed to extreme pH solutions or high
temperatures. this would result in less enzyme-substrate complexes
diffusion
the net movement of substances from an area of high to low
concentration, down a concentration gradient and can be across a partially permeable
membrane
concentration gradient
the difference in concentration between two areas
surface area to volume ratio (SA:V)
the size of the object compared with the area that is in contact with the environment
oseophagus
a muscular tube that takes food from the mouth to the stomach
alimetary canal
the digestive tract running from the mouth to the anus
peristalsis
the contraction and relaxation of muscles all along the alimentary canal that pushes the food along
amylase
an enzyme produced in the salivary glands and pancreas that speeds up the breakdown of starch into maltose
duodenum
the first part of the small intestine where food is broken down by the
pancreatic juices; lipids –> fatty acids + glycerol by lipases, proteins –> peptides/amino acids by proteases such as trypsin and carbohydrates like starch, that
get broken down into maltose by amylase
ileum
second part of the small intestine where the products of digestion are
absorbed, adapted with one cell thick wall (short diffusion distance), high surface area
(villi and microvilli) and high concentration gradient (capillaries)
bile
made in the liver, stored in the gall bladder and works in the duodenum where it emulsifies lipids and with pancreatic juices, neutralises stomach acid
colon
first part of the large intestine where water is reabsorbed
lipase
an group of enzymes produced in the pancreas that speeds up the
breakdown of lipids into fatty acids and glycerol
maltase
an enzyme produced in the small intestine that speeds up the breakdown of maltose into glucose
pancreas
an organ that produces and secretes enzymes such as amylase, lipases and proteases that make up the pancreatic juices and releases them into the duodenum
rectum
last part of the large intestine, where faeces are stored
stomach
food enters here after travelling down the oesophagus. stomach acid makes conditions acidic, perfect for pepsin which works here as it has an optimum pH
of 2. the acid kills any pathogens on the food. muscular walls contract to move food around and increase the chance of food coming into contact with enzymes
surface area
the total area occupied by the surface of an object, leaves have a large surface area to absorb maximum sunlight
villi
small, finger like projections on the surface of the ileum that increase surface area for maximum absorption. the walls of the villi are folded themselves (microvilli)
to increase surface area further
proteases
a group of enzymes that speed up the breakdown of proteins into
peptides/amino acids. an example being pepsin in the stomach with an optimum pH of 2 and other proteases get released into the small intestine from the pancreas
photosynthesis
an endothermic reaction where energy is transferred from the
environment to the chloroplasts by light from the sun. glucose is made.
glucose
made during photosynthesis. can be stored as starch, used straight away in respiration or used to make cellulose.
spongy mesophyll
a tissue found in plant leaves that is specialised for gas exchange
by having air spaces that allow the diffusion of gases to happen quicker
stomata
small holes found in the lower epidermis that open and close thanks to the guard cells. control the loss of water by closing during the night but open during the
day thanks to the guard cells to allow the diffusion of carbon dioxide and oxygen
waxy cuticle
on top of the upper epidermis that is insoluble so waterproofs the leaf
and reduces the evaporation of water but transparent to allow light to pass through
palisade mesophyll
a tissue found in plant leaves that are specialised to carry out
photosynthesis by being vertically packed to capture more sunlight and to store more chloroplasts
aerobic respiration
respiration that uses oxygen to release lots of energy from
breaking down glucose. the word equation:
glucose + oxygen –> carbon dioxide + water
the chemical equation:
C6H12O6 + 6O2 –> 6CO2 + 6H2O
anaerobic respiration
respiration without oxygen, that releases less energy than
aerobic respiration, represented by the word equation:
glucose –> lactic acid
ATP
adenosine triphosphate, a molecule made up of adenine (nitrogenous base, ribose (sugar) and three phosphates. releases energy quickly
cellular respiration
an exothermic reaction that continuously occurs in cells and
releases energy from nutrients
alveoli
tiny air sacs in the lungs at the end of the bronchioles where gas exchange occurs. adapted for gas exchange by having thin, moist walls for a short diffusion
distance, folded walls for a larger surface area and capillaries close by to maintain a high concentration gradient
bronchi
airways branching from the trachea that lead into the lungs
bronchioles
small airways branching from each bronchi in each lung
capillaries
thin, narrow blood vessels where the exchange of substances between the blood and tissues occurs, for example o2, glucose, co2
diaphragm
muscle that contracts and relaxes to change the volume of the thorax
and ultimately the pressure to control inhalation and exhalation
intercostal muscles
muscles between the ribs that contract and relax to move the
ribcage and change the volume and pressure during inhalation and exhalation
pleural membranes
airtight membranes covering the lungs and the thorax to
maintain pressure changes and stop the lungs from sticking to the ribcage
trachea
windpipe connecting the lungs to the mouth and nose. contains lots of cartilage to ensure it stays upright and does not collapse inwards with the pressure
changes
aorta
the main artery that takes oxygenated blood away from the heart, specifically the left ventricle, to the rest of the body
artery
type of blood vessel that carries blood under high pressure, away from the heart to the tissues of the body. most arteries carry oxygenated blood apart from the pulmonary artery. arteries have a narrow lumen, thick elastic, muscular and outer layers
atria
the two chambers at the top of the heart that receive blood from the veins and pump blood to the ventricles. much thinner walls compared to the ventricles
due to the distance the blood has to travel and therefore the blood does not need a high pressure
blood
a tissue contains red blood cells (which carry oxygen), white blood cells (phagocytes and lymphocytes), platelets (involved in clotting) and plasma (carries carbon dioxide, glucose and amino acids)
lymphocyte
a type of white blood cell that produces antibodies that are specific to a pathogen
phagocyte
a type of white blood cell that engulfs pathogens
plasma
the liquid component of blood that transports waste products like carbon dioxide, urea and heat and useful products like hormones, dissolved nutrients like
glucose and amino acids and antibodies
platelets
fragments of cells found in blood that are involved in clotting as when exposed to the air it causes the soluble fibrinogen to change to insoluble fibrin which acts as a net, collecting RBCs, forming a clot
red blood cells
cells found in blood that contains haemoglobin that transports
oxygen. they have a biconcave shape to increase surface area so more oxygen can be absorbed, no nucleus and contain haemoglobin so more oxygen can be carried
coronary heart disease (CHD)
a disease caused by the build-up of fatty deposits inside the coronary arteries (arteries supplying blood to the heart), causing them to
narrow and reduce blood flow to the heart, resulting in less oxygen and glucose to the heart, reducing aerobic and increasing anaerobic respiration, eventually
resulting in a heart attack
haemoglobin
red protein found in red blood cells that is responsible for transporting oxygen
heart
the organ the pumps blood around the body in the closed, double
circulatory system in humans
veins
a blood vessel that carries blood at low pressure back to the heart, often deoxygenated apart from the pulmonary vein. contains a wider lumen, thinner elastic, muscular and outer layers and valves
hepatic artery
artery that supplies the liver with oxygenated blood
hepatic portal vein
carries blood from the intestines to the liver, high in glucose
hepatic vein
vein that carries blood away from the liver back to the heart
pulmonary artery
the artery that takes deoxygenated blood from the heart, specifically the right ventricle to the lungs
pulmonary vein
the vein that carries oxygenated blood from the lungs to the
heart, specifically the left atrium
renal arteries
the arteries that supply blood to the kidneys
renal veins
veins that take blood away from the kidneys
vena cava
the vein that takes deoxygenated blood back to the heart, specifically
the right atrium, from the body
ventricles
the lower chambers of the heart that receive blood from the atria and pump blood out of the heart into the arteries at high pressure
white blood cell
cells of the immune system that protects the body from pathogens by producing antibodies or engulfing them
root hair cells
specialised cells that are responsible for the absorption of water and mineral ions from the soil by having a large surface area for maximal absorption and lots of mitochondria form the active transport of mineral ions
