Final exam definitions Flashcards
Active transport
-Movement of particles from lower to higher concentration using energy from ATP that has been created during respiration.
-Movement is through carrier proteins.
Amphipathic
A molecule that is partly hydrophilic and partly hydrophobic.
Autotrophic
An organism that synthesizes its organic molecules from simple inorganic substances.
Bilayer
Two rows of phospholipids, with the fatty acids pointing towards each other and the phosphates on the outside.
Cell cycle
Cells arise by the division of existing cells, grow, and then divide.
Cell respiration
The controlled release of energy from organic compounds to produce ATP.
Chemiosmosis
The process by which the synthesis of ATP is coupled to electron transport via the movement of protons.
Cytokinesis
Division of the cytoplasm.
Deamination
The removal of NH2 from an amino acid.
Decarboxylation
Chemical reaction that releases carbon dioxide.
Activation energy
The energy required by a substrate molecule before it can undergo a chemical change.
Active site
A region of an enzyme molecule where the substrate molecule binds.
Adhesion
The force by which individual molecules stick to surrounding materials and surfaces.
Anabolism
The synthesis of complex molecules from simpler molecules, including the formation of macromolecules from monomers by condensation reactions.
Catabolism
The breakdown of complex molecules into simpler molecules, including the hydrolysis of macromolecules into monomers.
Catalyst
A substance that speeds up the rate of a chemical reaction. Catalysts are effective in small amounts and remain unchanged at the end of the reaction.
Cohesion
The force by which individual molecules stick together.
Competitive inhibitor
A substance that binds to the active site, slowing down or blocking enzyme action.
Condensation
A reaction in which two molecules combine to form a larger molecule, producing water as a by-product.
Denatured
When a protein loses its three-dimentional shape.
End-product inhibition
When the product of the last reaction in a metabolic pathway inhibits the enzyme that catalyses the first reaction of the pathway.
Enzyme
A biological catalyst made of protein.
Enzyme inhibitor
A substance which slows or blocks enzyme action.
Hydrolysis
A chemical process in which a molecule of water is added to a substance, splitting it into smaller subunits.
Hydrophilic
Attracted to water; hydrogen bonds readily form between the phosphate head and water molecules.
Isomer
Two or more compounds with the same formula but a different arrangement of atoms in the molecule, and different corresponding properties.
Metabolic pathway
A sequence of enzyme-catalyzed biochemical reactions in cells.
Metabolism
The web of all the enzyme-catalyzed reactions in a cell or organism.
Monomer
A molecule that can be bonded to other identical molecules to form a polymer.
Non-competitive inhibitor
A substance that does not bind to the active site but to another part of the enzyme, slowing or blocking enzyme action.
Product
What the substrate is converted into in a reaction where the substrate is catalyzed by an enzyme.
Rate of reaction
The amount of substrate that has disappeared from a reaction mixture, or the amount of product that has accumulated, in a period of time.
Substrate
The starting substrate in a reaction catalysed by an enzyme. It is the molecule is acted upon by the enzyme.
Synthesis
The production a new substance as a result of a chemical or biological reaction involving simpler substances.
Diffusion
-Movement of particles from higher to lower concentration through the phospholipid bilayer.
-Movement is passive (no direct energy is needed).
DNA sequencing
Investigation of the sequence of bases in particular lengths of DNA.
Electron carrier
A substance that can accept and release electrons.
Endocytosis
The formation of vesicles as the plasma membrane pinches inwards, taking material into the cell.
Epigenetics
-The study of heritable changes in gene activity that are not caused by changes in the DNA base sequences.
-Mechanisms that produce such changes are DNA methylation and histone modifications.
Exocytosis
Vesicles fuse with the membrane and material is exported from the cell.
Exon
The section of the gene that carries meaningful information (that codes for amino acids).
Facilitated diffusion
The passive movement of particles from higher to lower concentration through integral proteins (carrier or channel proteins).
Gel electroporesis
A process used to separate proteins or fragments of DNA according to size.
Gene
A heritable factor that consists of a length of DNA and infleunces a specific characteristic.
Genetic profiling
The identification of individual organisms or species using DNA.
Genome
The whole of the genetic information of an organism.
Genotype
The ‘genetic makeup’ of a person; the genetic information in the cell.
Homeostasis
The maintenance of a constant internal environment.
Hypertonic
When the external solution is more concentrates (has a higher solute potential) than the cell solution (cytosol) and there is a net flow of water out of the cell by osmosis).
Hypotonic
WHen the external solution is less concentrated (has a lower solute potential) than the cell solution (cytosol) and there is a net inflow of water into the cell by somosis.
Intron
Non-coding nucleotide sequence of the DNA of chromosomes, present in eukaryotic chromosomes.
Isotonic
When the external solution is the same concentration (has the same solute potential) as the cell solution (cytosol) and there is no net entry or exit of water from the cell by osmosis.
Methylation
The reversible addition of a methyl group (-CH3) within the chromatin, to histone tails or usually to the DNA molecule itself.
Mitotic index
The number of cells undergoing mitosis divided by the total number of cells visible.
Mutation
A change in the amount or the chemical structure (i.e. base sequence) of DNA of a chromosome.
Osmolarity
The concentration of a solution expresed as the total number of solute particles per liter.
Osmosis
The passive diffusion of water molecules across a partially permeable membrane from a lower to higher solute concentration.
Passive transport
No direct energy needed.
Phenotype
The outward effect of the genotype on the body.
Phenotypic expression
Physical characteristics.
Photophosphorylation
The formation of ATP using light energy (in the light-dependent step of photosynthesis in the grana).
Polymerase chain reaction (PCR)
A technology used to amplify a single piece or very few pieces of DNA, generating many thousands of copies.
Promotor
A region of DNA that initiates transcription of a particular gene.
Saprotrophs
Heterotrophs that obtain organic nutrients from dead organisms by external digestion.
Transcription
The synthesis of mRNA copies from the DNA base sequences by RNA polymerases.
Transcription factor
Protein that binds to specific DNA sequences to control the transcription of mRNA.
Translation
The synthesis of polypeptides on ribosomes.
Variable number tandem repeats (VNTRs)
-Short base sequences that show variation between individuals in terms of number of repeats.
-These major lengths of noncoding DNA are used in genetic profiling.
Supercoil
A DNA double helix that has undergone additional twisting in the same direction as, or in the opposite direction from, the turns in the original helix.
Heritable
Can be passed from one generation to another, from parents to offspring.
Balanced diet
Essential and non-essential nutrients, taken in correct proportions.
Bile salts
Organic salts composed of cholic acid, which is manufactured by the liver from cholesterol, that are combined with an amino acid-sodium complex.
Diabetes
Failure to regulate blood glucose levels.
Diabetic
A person whose body is failing to regulate blood glucose levels correctly.
Dietary minerals
Essential chemical elements that cannot be made by the body.
Digestive juice
The fluid secreted onto food in the gut to aid digestion.
Community
A group of populations of different species living and interacting with each other in a habitat.
Consumers
Heterotrophs that feed on living organisms by ingestion.
Detritivores
Heterotrophs that obtain organic nutrients by internal digestion.
Ecology
The study of living things in their environment.
Ecosystem
A community of organisms and the environment in which they live and interact.
Endopeptidase
A protease enzyme that breaks peptide linkages in the interior of the protein, producing shorter-chain polypeptides.
Endothelium
The innermost lining layer of arteries and veins. It is once cell thick, and is very smooth, reducing friction between blood cells and blood vessels.
Essential nutrient
A nutrient that cannot be synthesized by the body and therefore, has to be included in the diet.
Exsitu conservation
The preservation of species outside their natural habitats
Food chain
A sequence of organisms within a habitat in which each is the food of the next, starting with a producer, which is photosynthetic.
Food web
Interconnected food chains.
Gene pool
All the genes (and their alleles) present in an interbreeding population
Global warming
An increase in the average temperature of the Earth’s atmosphere
Greenhouse gases
Atmospheric gases that absorb infra-red radiation, causing world temperatures to be warmer than they otherwise would be.
Hypertension
A condition of persistently raised blood pressure
Mesocosm
An enclosed experimental area that is set up to explore ecological relationships. Because it is a contained experimental area, it can be closely controlled and variables can be monitored.
Mucosa
The internal linings of lungs, trachea, and gut
Negative feedback
Feedback that counteracts any deviation from equilibrium and promotes stability.
Non-essential nutrients
Nutrients that are made in the body or that have a replacement nutrient that can fulfill their dietary purpose.
Nutrient
A chemical substance found in foods that is used in the human body.
Population
A group of organisms of the same species that live in the same area at the same time.
Positive feedback
Feedback that increases change by promoting deviation from an equilibrium.
Reduction
Addition of electrons to a substance.
Reproductive isolation
Occurs when two potentially compatible populations are prevented from interbreeding.
Resolution
The ability to tell that two objects that are very close together are distinct objects rather than just one. (look at unit 1 flashcards)
Speciation
The evolution of new species.
Species
Groups of organisms that can potentially interbreed to produce fertile offspring.
Sustainability
The use of global resources at a rate that allows natural regeneration and minimizes damage to the environment.
Variable
A factor that is being changed, investigated, or kept the same in an investigation.
Alleles
Different versions of the same gene (one from the father, one from the mother)
Allergen
Something that causes an allergic response
Allergy
An exaggerated response by the body to antigens
Altricial
Born in an undeveloped state after a short gestation period
Analogous structures
Anatomical features that appear similar in structure but have a different evolutionary origin
Antibiotics
Organic compounds that selectively inhibit or kill other microorganisms
Antibody
A protein produced by B lymphocytes when in the presence of a specific antigen, which then binds with the antigen, aiding its destruction.
Antidiuretic hormone (ADH)
A hormone secreted by the pituitary gland that controls the permeability of the walls of the collection ducts of the kidney.
Antigen
A substance capable of binding specifically to an antibody and triggering an immune response
Basophil
A type of white blood cell
Blood pressure
The pressure of blood flowing through the arteries
Cardiac cycle
The sequence of events of a heartbeat, by which blood is pumped all over the body
Carpel
Female part of a flower, consisting of stigma, style, and ovary (+ ovule)
Clade
A group of organisms that have evolved from a common ancestor
Cladistics
A classification system used to construct evolutionary trees. Organisms are categorized based on shared derived characteristics that can be traced to a group’s most recent common ancestor and are not present in more distant ancestors. Characteristics can be anatomical, physiological, behavioral, or genetic sequences.
Cladogram
A diagram used in cladistics that shows relations among organisms
Co-dominant
Both alleles show through in the phenotype
Corpus luteum
A hormone-secreting structure that develops from an ovarian follicle after an oocyte has been discharged. It degenerates after a few days unless pregnancy has begun
Cortical granules
These prevent polyspermy during fertilization
Diastole
Relaxation of the heart muscle
Dichotomous key
A stepwise tool for identification where there are two options based on different characteristics at each step
Disease
A disorder of structure or function in the body
Dominant
An allele that always shows through. An allele that causes the homozygous form and the heterozygous form to look the same as each other.
Embolus
A thrombus that breaks free and is circulated in the bloodstream
Endocrine glands
Glands that secrete hormones directly into the bloodstream
Endometrium
The lining of the uterus
Epidemiology
The study of the occurrence, distribution, and control of diseases
Evolution
Fertilization
The fusion of male and female gametes to form a zygote
Freeze-etching
A process during which cells are rapidly frozen and then fractured
ametogenesis
The production of sex cells (gametes)
Gas exchange
The exchange of gases between an organism and its surroundings, including the uptake of oxygen and the release of carbon dioxide in animals and plants.
Genetic modificatino or engineering
The transfer of a gene from one organism (the donor) to another (the recipient)
Germination
The resumption of growth by an embryonic plant in a seed or fruit, at the expense of stored food.
Gestation
The period of development in the mother’s body, lasting from conception to birth
Gradualism
Evolution that takes place through a long sequence of continuous intermediate forms
Hepatitis B
A disease of the liver caused by a virus
Heterozygous
Two different alleles for a particular characteristic in each cell
Hierarchy
A structure made from many different levels. In biology, it relates to the different levels of classification from kingdom to species.
Homologous structures
Anatomical features that occupy similar positions in an organism, and have an underlying basic structure in common, but may have evolved different functions.
Homozygous
Two identical alleles for a particular characteristic in each cell
Hormones
Chemical messengers that are produced and secreted from the cells of the ductless or endocrine glands
Hybridoma cells
A hybrid cell used in the production of monoclonal antibodies, created by fusing a B lymphocyte with a cancer cell
Immunity
The ability of the body to resist an infection by a pathogen
Intercalated disc
A double membrane with gap junctions, through which are cytoplasmic connections between adjacent cardiac cells
Jaundice
Condition in which the skin develops a yellowish tinge along with the whites of the eyes (sclera)
Joint
The junction between two or more bones, usually formed of connective tissue and cartilate
Karuogram
Photograph showing individual chromosomes arranged in homologous pairs in descending order of size
Karyotype
The number and type of chromosomes in the nucleus
Lactation
The production and secretion of mil by the mammary glands after birth
Linked genes
Characteristics controlled by genes on the same chromosome
Malnutrition
A serious condition that occurs when a person’s diet doesn’t contain the right quantity or balance of nutrients
Malphigniant tubule
A tubular excretory organ that opens into the gut in insects
Mast cell
White blood cell found in connective tissue
Melanism
Development of a dark-colored pigment, melanin, in the outer surface of an organism
Menstrual cycle
Monthly cycle of ovulation and menstruation in human females
Menstruation
Shedding of the endometrium from the uterus
Meristem
A group of cells in plants that retains the ability to divide (indefinitely) by mitosis
Micropropagation
Technique that rapidly multiplies stock plant materia, in vitro, to produce large numbers of offspring, all genetically-identical to the parent platn
Monoclonal antibody
Antibody produced by a single clone of B lymphocytes and consists of a population of identical antibody molecules
Monohybrid
Genetic cross involving one characteristic/gene, such as eye color
Myogenic
The control of the hearbeat originates within the heart muscle itself, rather than from the nervous system
Oogenesis
The production of egg cells in ovaries
Osmoconformer
Animal that maintains the osmotic concentration (osmolarity) of its cells and body fluids at the same concentration as that of the environemnt
Osmoreceptor
Receptor in the central nervous system that resopnds to chances in the solute potential of the blood
Osmoregulation
Control of the water balance of teh blood, tissue, or cytoplasm of a living organism
Osmoregulator
Animal that controls its internal osmolarity independently of environmental conditions
Ovarian follicle
A fluid-filled spherical sac that contains and nourishes an immature egg, or oocyte
Ovulation
Release of oocyte (egg) from ovary
Parturition
The act of giving birth
ogen
Organism or virus that causes a disease
Photoperiodism
Day-length control of flowering in plants
Phytocrome
A photoreceptor protein that is able to absorb light of a particular wavelength and change its structure as a consequence
Placenta
A temporary organ that joins the mother and fetus, transferring oxygen and nutrients from the mother to the fetus, with carbon dioxide and other waste material transported from fetus to mother.
Pollination
The transfer of pollen from anther to stigma
Polygenic inheritance
The inheritance of phenotypes that are determined by the collective effect of several genes. It leads to continuous variation.
Polymorphic
There are a number of possible genotypes at the locus for any specific marker 1
Polyploidy
An abrupt alteration in the number of whole sets of chromosomes
Polyspermy
Fertilization of an egg by many sperm
Precocial
Species in which the young are relatively mature and mobile from the moment of birth
Primary defence
The first line of defence against a disease, preventing the pathogen from entering the body in the first place
Proteome
The entire set of proteins expressed by the genome of the individual organism
PPunctuated equilibria
Where long periods of relative stability are punctuated by periods of rapid evolution
Recessive
Hidden by a dominant allele. An allele that affects an organism only if it is present in the homozygous state.
Recombinant DNA
DNA that has been artificially changed, involving joining together genes from different sources (typically from different species)
Reproduction
The production of new individuals by an existing member or members of the same species
Resting potential
The potential difference across a nerve cell membrane when it is not being stimulated. It is normally about -70 millivolts (mV).
Secondary sexual characteristics
Physical characteristics that develop at puberty that distinguish the sexes but are not directly involved in reproduction (e.g. facial hair in males, development of breasts, and wider hips in females).
Seed dispersal
The carrying of the seed away from the parent plant
Sex linkage
A special case of linkage that occurs when a gene is located on a sex chromosome (usually the X chromosome)
Skeletal muscles
Muscles that are attached to the moveable parts of the skeleton. Their contraction brings about locomotion.
Spermatogenesis
The production of sperm in testes
Stamen
Male part of flower, consisting of anther an filament
Synovial fluid
A thick, viscous fluid found in a joint for lubrication
Systole
Contraction of the heart
Target organ
The specific site where a hormone has an effect
Taxonomy
The science of classification
Tension
The force that is transmitted throuhg a substance when it is pulled tight by forces acting from opposite ends
Thrombosis
The formation or presence of a blood clot in a blood vessel
Thrombus
A blood clot formed within a blood vessel
Tidal volume
The volume of air that a human breathes in and out of their lungs while at rest
Translocation
The movement of manufactured food (e.g. sugar and amino acids) that occurs in the phloem tissue of the vascular bundles
Transpiration
The evaporation of water from the spongy mesophyll tissue and its subsequent diffusion through the stomata
Tropism
A growth response of plants in which the direction of growth is determined by the direction of the stimulus
Ultrafiltration
High hydrostatic pressure forces small molecules such as water, glucose, amino acids, sodium chloride, and urea through tiny pores in the capillaries of the glomerulus and into the Bowman’s capsule.
Ventilation rate
The number of breaths (inhalations or exhalations) per minute
VenVentilation system
A pumping mechanism that moves air in and out of the lungs efficiently, thereby maintaining the concentration gradients of oxygen and carbon dioxide for diffusion.
Vitamins
Organic compounds that are only required in tiny doses.
Zona pellicuda
The coat that surrounds the oocyte. It is made of glycoprotein.
Zoonoses
Diseases of other animals that can be transmitted to humans.
