Biology 2 - Genes and Health

define osmosis

the net movement of water from an area of lower concentration to higher concentration through a partially permeable membrane, which doesn’t use energy from respiration

define diffusion

the movement of particles from an area of higher concentration to and area of lower concentration

define active transport

the movement of particles from an area of lower concentration to an area of higher concentration against the concentration gradient while using energy from respiration

what proteins are involved in facilitated diffusion?

carrier and channel

what molecules pass across a membrane via facilitated diffusion?

charged molecules (channel proteins) and large molecules (carrier proteins)

what is endocytosis?

a substance is taken across a membrane by being engulfed by the membrane and pinched off into the cell creating a vesicle

what is exocytosis?

a substance is released from a cell when the vesicle fuses with the membrane and releases the substance out of the cell

what is a membrane made of?

phospholipid bilayer

what is Fick’s law?

rate of diffusion = (surface area x concentration difference)/thickness of membrane

how are lungs adapted for rapid gas exchange?

massive surface area (alveoli)

what is ATP used for?

the cell can’t get all its energy from glucose so the energy released from glucose is used to make ATP which stores and releases energy

what is ATP often known as?

universal energy currency

where is ATP formed?

mitochondria via aerobic respiration

what is the role of cholesterol in a membrane?

provides structure and support

what is the role of protein in a membrane?

selective transport of molecules, and communication

what is the role of glycoproteins in a membrane?

act as receptors, bind to signalling molecules

what is the role of glycolipids in a membrane?

cell recognition and stability

what is the role of phospholipids in a membrane?

controls the cell’s internal environment

what is the aqueous environment inside the cell?

cytoplasm

what is the aqueous environment outside the cell?

tissue fluid

what are the two 3D structures that a protein could have?

globular or fibrous

what are the characteristics of globular structure?

round, compact, multiple polypeptide chains, coiled, hydrophilic inside, hydrophobic outside, soluble

what are the characteristics of fibrous structure?

long insoluble polypeptide chains, tightly coiled around each other, lots of bonds makes it strong, often found in supportive tissue

what is the order of polypeptides structure?

primary (sequence of amino acids), secondary (alpha helixs, beta pleated sheets), tertiary (3D specific shape), quaternary (2+ polypeptides forming a protein)

what is the function of DNA?

to store genetic information

what is the function on RNA?

to transfer genetic information

how do ribosomes work with RNA?

they read RNA to make polypeptides (translation)

what are DNA and RNA types of?

nucleic acids

what is a gene?

a length of nucleotide bases that provides a code to sequence amino acids to form a polypeptide

what are exons?

coding regions of DNA (genes)

what are introns?

non-coding regions of DNA

what is DNA made up of?

two polynucleotide strands

what is RNA made of?

a single stranded polynucleotide

what are two examples of RNA?

messenger and transfer

when is RNA made?

it’s copied from DNA for protein synthesis

what is transcription?

the process of DNA being copied into mRNA to transfer genetic information to the ribosomes