Exam review

Active transport

from [low] to [high], uses ATP energy

Passive Transport

from [high] to [low] no energy needed

diffusion

solute moves from [high] to [low], passive

osmosis

water moves from [low solute] to [high solute], passive

channel proteins

proteins in cell membrane that allow substances to move through

hypertonic

region with higher [solute]

hypotonic

region with lower [solute]

isotonic

both sides of membrane have the same [solute]

vesicular transport

substances enter or exit a cell by vesicles

exocytosis

vesicles remove a substance from a cell, active transport

endocytosis

vesicles form from cell membrane to bring a substance inside the cell, active transport

phagocytosis

endocytosis where cell engulfs solid substance that is brought into cell

pinocytosis

type of endocytosis where folds in and pinches off to bring liquids into the cell

receptor mediated transport

transport across a cell membrane that involves the use of a receptor to control the transport process. may open a protein channel on the membrane or initiate endocytosis

what happens to blood cells in hypotonic solution

they swell, burst, and become ghosts because they are hard to see

what happens to blood cells in hypertonic solution

they strink and denature

phosphlipid

hydrophilic head hydrophobic tail, form bilayer with heads on the outside

glycoproteins

carbohydrate attached to a protein on outside of membrane. identify cells as self to immune system

cholesterol

steroid that maintains fluidity of the membrane. increases fluidity in low temperature and decreases fluidity in high temperature

integral protein

protein that is embedded in the membrane so one side is outside of the cell and the other is inside. relays signals to the cell

channel protein

protein that provides a hydrophilic gateway for ions and water to enter and exit the cell

peripheral protein

protein exposed to either the inside or outside of the cell, not both. may shuttle substances around the membrane or partner with another protein to signal instructions to the cell. adds structural support

davson danielli model

lipid bilayer with protein layers sandwiched around it

how was the davson danielli model debunked

microscopes showed globular structures going through the membrane and movement

fluid mosaic model: fluid

the membrane is flexible and its components are constantly changing

fluid mosaic model: mosaic

membrane consists of many parts with many functions

carrier proteins

binds to a molecule and transports it across the lipid bilayer

how do carrier proteins actively transport substances

binds to P from ATP and intakes a particle. once particle binds to the protein, it changes shape and the particle ends up exposed to the other side of the membrane

amphipathic

having both hydrophilic and hydrophobic parts

shrunken cell

crenated or plasmolysed

swelled cells

lysed or turgid

Negative Feedback

A process whereby a change in a system will inhibit further change/return to homeostasis

Receptor

Receives information about the body’s internal conditions

integrator

receives messages from receptors and sends to effectors

effector

receives instructions from integrator and makes changes to the body

communication system

a means of relaying messages between components of the system

hormones

chemical that sends regulatory messages within the body

target cells

elicits a specific response due to receptors binding to hormone

how do steroid hormones work

enter nucleus and binds to DNA to regulate protein synthesis via receptors in the DNA

how do protein hormones work

attaches to receptor on cell membrane, turns atp to camp, regulates enzymes

homeostasis

body’s maintenance of a relatively stable internal physiological environment

what hormones regulate blood sugar?

insulin, glucagon, epi/norepi, cortisol

insulin

released in B islets of Langerhans (pancreas) in response to high blood sugar, increases cell uptake of glucose, stimulates liver to produce glycogen

glucogon

released by a cells in islets of Langerhans (pancreas) in response to low glucose in blood, stimulates glycogen breakdown

cortisol

released from adrenal cortex to break down muscle protein, convert amino acids to glucose

ACTH

released from anterior pituitary gland, causes release of cortisol from adrenal cortex

Epinephrine/norepinephrine

released by adrenal medulla in response to stress. increases heart rate, breaks down glycogen, stimulates cell metabolism

T3/T4

released by thyroid in response to TSH to increase metabolism

TRH

released by hypothalamus in response to low T3/T4. stimulates TSH release in pituitary gland

TSH

released in pituitary gland in response to TRH. stimulates t3/t4 release in the thyroid

what happens when stressed? corticoid pathway

hypothalamus releases hormone that stimulates ACTH from pituitary gland which stimulates adrenal cortex to release glucocorticoid

how does insulin work

binds to insulin receptors of cells which activates a dormant protein to stimulate glut4 to move to the cell membrane and provide a channel for glucose to come in

why is insulin important even though there are many other non-insulin dependant gluts other than glut4

glut4 found in cardiovascular muscle cells, skeletal muscle cells, adipose cells

adipose cell/adipocyte

fat storing cell

type 1 diabetes mellitus

body doesn’t produce insulin, can be due to diseased pancreases, requires regular injections or replaced islets of langerhans

type 2 diabetes mellitus

receptors desensitized to insulin, diet related

endocrine

directly into the blood stream, no ducts

gland

releases products to blood directly

hypothalamus

controls the pituitary gland via hormones, supplies the pituitary gland with hormones

pituitary gland

produces hormones

thymus

stimulates Tcell development in childhood

adrenal gland

releases epi, norepi, and glucocorticoids

pineal gland (brain)

releases melatonin, regulates rhythmic activities

thyroid

releases T3 and T4 to regulate metabolism

pancreas

releases insulin and glucagon via islets of langerhans to regulate blood sugar

ovary

releases estrogen (female secondary sex characteristics) and progesterone (prepares uterus for egg)

testes

release testosterone. stimulates sperm production and male secondary sex characteristic development

stress response epi pathway

stress causes sympathetic nerves to stimulate release of epi and norepi from adrenal medulla

recombinant DNA

strand of DNA formed from pieces from 2 or more sources

electrophoresis

uses an electric field and a gel to separate fragments by charge and size

gene cloning

isolated and copying a gene by inserting its DNA sequence into a vector then a cell and allowing it to reproduce

gene splicing

joining pieces of DNA from different sources using recombinant DNA technology

plasmid

small loop of DNA separate from main chromosome. commonly used for recombinant DNA

Restriction Enzyme

enzyme specific to a palindromic base sequence of usually 4-6 bases. cuts both strands of DNA at each place the sequence occurs

transformation

introduction of outside DNA molecule into a cell, causing a new phenotype

vector

type of DNA molecule, usually plasmid or virus, that is a vehicle from transferring recombinant DNA between cells

antibiotic

a chemical substance that kills or inhibits growth of a microorganism

RFLP’s (restriction fragments length polymorphisms)

sequences of DNA that vary between individuals, used in DNA profiling

DNA profiling/fingerprinting basic steps

RFLP selected, restriction enzymes cut, electrophoresis used, fluorescent chemical EtBr applied, banding produced

process of gene cloning via gene transfer to bacteria

isolate target gene via restriction enzyme, place gene in plasmid and stick with DNA ligase, CaCl2 treated and heat shocked cells introduced, antibiotic applied, survivors reproduce

why is it useful to cut the plasmid with the same RE used to isolate the target gene?

the ends will fit together better. sticky to stick and blunt to blunt is strongest

applications of gene transfer to bacteria

HGH can be extracted from the bacteria or cloned pest resistance genes can be extracted and used on plant cells

restriction fragment

fragment that results from restriction enzyme digestion

sticky ends

hangover pieces of DNA in restriction fragments. DNA ligase works best with this

competent cell

can take up foreign DNA

Polymerase chain reaction (PCR) benefits in comparison to gene cloning using RE

reliable, precise, fast, inexpensive

steps of PCR

denaturation, annealing, elongation

PCR: denaturation

1 minute at 94-96 C, breaks hydrogen bonds to split the strands of DNA

PCR: annealing

45 s at 50-65C, synthesized primers anneal, bracketing target region

PCR: elongation

72C for 2 minutes taq polymerase builds 5’-3’ starting at the primer

when is first target DNA synthesized in PCR

2 made after the 3rd cycle

CRISPR stands for

clustered regularly interspaced short palindromic repeats

what is CRISPR

a library of viral DNA in bacteria used to recognize viral attack and cut up viral DNA using cas9

how can CRISPR be used for genetic engineering

guideRNA can be engineered as any base pair known to cause disease and be used with cas9 to replace it or just cut it out of DNA

what are 4 benefits of CRISPR to restriction enzymes?

precise, cheap, quick and can cut and replace DNA in one go

how does new viral DNA get added to the CRISPR system?

a cas1 protein is synthesized to cut viral DNA and spacer is added to CRISPR

Hammerling experiment

cut acetabularia cells and observed regrowth. transplanted a nucleus from another type of cell into it and observed regeneration

hammering finding

only nucleus-containing segments could regenerate. cells containing the nucleus of another cell caused it to express the genes of the nucleus’ original cell

hammering conclusion

hereditary information is contained in the nucleus

griffith experiment

injected mice with 2 versions of a bacteria, one deadly s one harmless r. killed s bacteria with heat and injected with r bacteria