Chapter 1 - cell structure and function Flashcards
homeostasis
potential energy
the body’s ability to maintain a stable and constant internal condition
energy stored within a physical system
pathogen
disease-causing agent; usually a bacteria, virus or fungi
- enzyme
* co-factor
- substance that helps catalyze chemical reactions
- A co-factor is a chemical compound that is required for certain enzymes — called conjugated enzymes — to become active e.g. vitamins & minerals serve a so-factors
macronutrient
micronutrient
phytochemical
nutrient the body requires in large amounts (i.e. fat, carbohydrates, protein)
nutrient the body requires in very small amounts (i.e. vitamins and minerals)
chemical substance obtained from plants that is biologically active but non-nutritive
epithelial tissue
tissue composed of cellular layers that protect outer surfaces of the human body such as skin, mucosa and intestinal lining
muscle tissue
tissues consisting of bundles of cells that contract when stimulated
- nucleus
- gene
- chromosomes
- organelle where genetic material is housed
- a particular sequence in DNA or RNA that controls the expression of a protein, and by extension influences the characteristics of an organism
- organised structure of DNA, found within cells, that contains the genes of an organism
genetic polymorphism
variation in the form of one or a sequence of genes
diurnal
daily cycle e.g. of hormone release
lipid
organic substance that is insoluble in water; provides structure, storage and messenger functions in the body
cholesterol
Cholesterol is an essential part of our bodies; it makes up part of all cell membranes and helps produce several hormones. Some cholesterol comes from our diet, but most is made in the liver from saturated fats.
phospholipids
a type of lipid with a hydrophilic phosphate group “head” and hydrophobic fatty acid “tail” that forms cell membranes
hydrophilic
hydrophobic
- strong affinity for water
* lack of affinity for water
mitochondria
cristae
- organelles that supply the cells’ energy/ATP
* the inner membrane is folded into cristae
oxidize
to combine with oxygen
adenosine triphosphate (ATP)
adenosine molecule with 3 phosphate groups that supplies energy for the cell
mitochondrial density
mitochondrial quality
- quantity of mitochondria per unit volume
* specific attributes of mitochondria
reactive oxygen species (ROS)
various substances produced as a byproduct of metabolism that are highly reactive due to the unpaired electron shell
free radical
free radicals are atoms or molecules with an unpaired electron and are produced all the time in our bodies as a result of normal metabolism and energy production. In large numbers they have the potential to wreak havoc on the body but some help to fight disease, kill bacteria and heal cuts. the problems arise when too many are produced and they cannot be controlled by the body’s defence system.
- transcription
* translation
- construction of mRNA from a DNA molecule
* forming a protein molecule based on the information contained in the mRNA
endoplasmic reticulum
is a circulatory network located inside the cytoplasm. Rough ER (with ribosomes) is the site of protein synthesis after receiving message from DNA
golgi apparatus
Cytoplasmic organelle necessary for the modification and transport of proteins. The golgi apparatus contains cistern (like holding tanks) stacked on one another. they act like chaperones, engulfing the proteins and transporting them to the cell membranes.
glycoproteins
protein that contains a carbohydrate group, involved in membrane integrity
- lysosome
* peroxisome
- enzyme containing vesicles - cellular garbage disposal!
* cytoplasmic organelle with enzymes that help with the breakdown of fatty acids and other macromolecules
- receptor-ligand binding complex
- signal transduction
- second messenger
- A complex formed when a chemical and receptor in the cell membrane bind together
- conversion of one signal to another by a cell
- substance that mediates intracellular activity.
transport protein
protein that moves compounds across a membrane
- facilitated diffusion
2. active transport
- transport that requires a carrier molecule; occurs when diffusion on it’s own is not possible
- movement of particles from an area of low concentration to an area of high concentration; requires energy and enzymes
- substrate
2. co-enzyme
- substance acted upon by an enzyme
- non-protein compound that operate alongside enzymes - composed wholly or partly of vitamins. they are necessary to assist in the enzyme catalysed reactions
- lock & key model
2. induced fit model
- model that explains enzyme specificity
2. model that suggests enzymes are rather flexible structures
