Chapter 3 Lecture

what is the basic unit of the body

cells

what determines the function of something

the structure

what are the 3 major parts of a cell

nucleus, cytoplasm, and cell membrane

what makes up the cell membrane?

glycoprotein (protein attached to carb), glycolipid, cholesterol, phospholipid blilayer, etc.

purpose of cell membrane

regulate entry/exit of substances, role in signal transduction

what can easily diffuse through the cell membrane

small nonpolar molecules

are the phospholipid heads polar or nonpolar? tails?

head: polar, hydrophillic. tails: nonpolar, hydrophobic

cholestorol purpose in membrane

helps stabilize membrane and helps keep it impermeable to water-soluble substances, affect fluidity of membrane

whats the importance of proteins and lips being able to move in the membrane

maintains mosaic fluidity structure

some functions of the membrane proteins:

act as a pore, channel, receptor, enzyme, help with cell contact/identification

Cell Adhesion Molecule (CAM) function

help cells to bind to another surface

carbohydrates function in cell membrane

help to function in cell recognition and interaction. permeable to lipid soluble markers. use carbs to identify

mutation in Na+ (sodium) channels can cause what

inability to feel pain or extreme pain conditionsm

mutation in potassium channel (K+)

can disrupt electrical activity of heart, disturb heart rythym, and/or impair hearing

abnormal Cl- channels

cause of cystic fibrosis, leads to production of thick mucus causing difficulty in breathing/clogged pancreas/salty sweat

what are two types of CAM and their function

Selectins: help coat white blood cells and anchor them by providing friction as they move.

Integrins: direct white blood cells through capillary walls towards site of infections, guide embryonic cell towards maternal cells to form placenta and establish connection between nerve cells

cytoplasm consists of:

networks of membranes and organelles suspended in cytosol (cytosol +organelles)

cytoskeleton function and location

within the cytoplasm. supporting framework of diff protein rods/tubules that help in movement. help maintain cell shape and transport within cell. made up of microtubules/actin/filaments

what are ribosomes composed of?

protein and rna

where can ribosome be found

free floating around or on rough ER

ribosome function

provide structural support, and produce proteins

what is a endoplasmic reticulum

a membrane bound sac, canal and vesicle

what are the types of endoplasmic reticulum

smooth and rough ER

rough ER function

has ribosomes attached. conduct protein synthesis

smooth ER function

no ribosomes, conduct lipid synthesis

does liver have more rough or smooth ER?

smooth ER

vesicle function/components

circular, has phosoplipidbilayer. can transport things such as waste or proteins in them

golgi apparatus function

sort, modify and package thngs like protein and lipids, send them in vesciles to areas in/out of cell

mitochondria what is it and its function

a membrane-bound fluid-filled sac, has inner/outer membrane. outer membrane less permeable. function of mitochondria: produce atp

what process take place in the inner membrane of the mitochondria

cellular respiration

lysosome function

small membranous sacs, contain enzymes that digest proteins/carbohydrates/nucleicacid/bacteria/debri/worn out cell parts.

peroxisomes function

membranous sac contains enzymes that digest lipids, alcohol and hydrogen peroxide

microfilament/actinfilament

tiny rods of actin, provide cellular movement such as muscle contraction

microtubules

larger tubules of tubulin, their rigidity maintains cell shape; helps make up cilia, flagella and centrioles

where can cilia be found

in respiratory system (helps move things like mucus and dust), on top of cells

flagella location

at end of sperm

intermediate filaments

composed of several proteins, have a cytoskeletal structure, support nuclear envelope

centrosome structure/function

consists of two centrioles, near nucleus, composed of microtubules. function: provide spindle fibers during mitosis which distribute chromosome to form daughter cells

cilia

modal extensions of cell membrane. found on top of cells, consist of microtubules in cylindrical pattern. function: propel muucus in respitory track or egg toward uterus.

flagella

modal extension, much longer then cilia. causes entire cell to move ex

example of flagella in human cell

sperm tail

melas

mutant gene in DNA of mitochondria.

krabb disease

caused by inability to produce one lysosomal enzyme. person cannot produce mylin for nerve cells, leads to severe damage of nervous system

ADL

caused by lack of protein in membrane of peroxisome. end up with fatty acid build up

nuclear envelope

porous double layered membrane made up of phospholipid bilayer. separates cytoplasm of nucleus from cytoplasm of cell. allow passage of certain substances like RNA

nucleolus

dense body of RNA/protein in nucleus. site of ribosome productionw

where are ribosomes produced?

nucleolus

chromatin

string like structure of DNA. consist of cell chromosome, each containing DNA that are wound around proteins. Function: stores info for protein synthesis

wha are the passive/physical processes of cell

diffusion, osmosis, facilitated diffusion, filtration

what are the active processes of cell

active transport, endocytosis, exocytosis, trancytosis

what is diffusion

movement of atoms/molecules/ions from high concentration to low concentration. does not require atp.

why does diffusion occur

due to constant movement of atoms/molecules/ions

what is facilitated diffusion

diffusion across the cell membrane through ion channels or transporters. moves from high to low concentration, no atp requires

what substances can be transported through diffusion

small, nonpolar, uncharged, molecules

what substances can be transported through facilitated diffusion

water-soluble substances, things like sodium/potassium/chloride/glucose/aminoacid

osmosis

movement of water across semi-permeable membrane. higher water concentration to lower water concentration

osmotic pressure

ability of osmosis to generate enough pressure to life a volume of water. he

when does osmotic pressure increase

as concentration of impermeant solutes increase

isotonic

same pressure of water in cell/out

hypertonic

higher osmotic pressure. cells in hypertonic lose water

hypotonic

lower osmotic pressure, cell will gain more water

why do we give saline solution to patients

it is isotonic to our cellular environment

filtration

process that forces molecules through membrane by exerting pressure. passive process(no atp)

when blood plasma leaves your capillaries, water and small solutes are filtred but large plasma proteins are not. what type of transport is this an example of

filtration

active transport

movement of substances across membrane from low to high concentration (against the concentration gradient. require ATP, uses carrier molecules in membrane

what way does concentration gradient move

high concentration to low concentration

what requires active transport to move through membrane

sugars, amino acids, calcium ions, hydrogen ions and sodium potassiun pump

sodium potassium pump does what

transport three sodium ions to outside of cell, and 2 potassium ions into the cell. requires atp

important of sodium potassium pump

helps maintain ion electrochemical gradient and muscle contraction/nerve transmission. makes inside of the cell more negative and outside more positive

endocytosis

movement of substance into cell inside vesicle. substances too large to enter by other methods enter this way. require atp

what are the three types of endocytosis

pinocytosis, phagocytosis, receptor-mediated endocytosis

pinocytosis

cell engulfs LIQUID

phagocytosis

cell engulfs solid particles

receptor-mediated endocytosis

membrane engulfs specific substances which are bound to receptor protein on the membrane, membrane folds inward to create vesicle

exocytosis

release of substance from cell. (leaving cell)

transcytosis

involves receptor-mediated endocytosis, then followed by exocytosis. transports substances from 1 end of cell to other or move substance across barriers formed by tightly connected cells

stages of cell cycle

interphase, mitosis, cytokinesis

interphase

cell grows, replicates DNA and maintain normal functions

cell spends majority time in what phase

interphase

phases of interphase

G1, Synthesis (dna replication), G2

which stage of cell cycle do fully differentiated cells go

G0

what is mitosis and what does it produce, where does it occur

division of the nucleus, produces 2 identical daughter cells. occurs in somatic cells

cytokinesis

division of cytoplasm

phases of mitosis

Prophase, Metaphase, Anaphase, Telophase

when does cytokinesis begin

beings during anaphase continues through telophase

frequency of cell division is ____ and varies by ____

is strictly regulated, varied by cell type

what cells divide often and continually

skin cells, intestinal, and blood-forming cells

how often do neurons divide

a specific number of times, then cease

what gets shorter each cell division

telomeres

cell division increases sa to volume ration true or false

true

contact inhibition

healthy cells stop dividing when they become too overcrowded

cancer

unctrolled cell division

what are the 2 genes that cause cancer

oncogenes, tumor supressorgenes

oncogenes

abnormal forms of genes that usually control cell cycle, but are overexpressed

tumor-supressor genes

usualy regulate mitosis but cant do that when inactivated

differentiation

process of speicilazation of cells

progenitor cells

partially specialized stem cells, daughter of stem cell. more specialized, have limited division capacity, and can only become a restricted set of mature cells

stem cells

Stem cells are unspecialized with unlimited self-renewal and broad differentiation potential

totipotent cells

can form all cell types in body plus extra embryonic or placental cells

pluripotent cells

can give rise to cel ltype that make up body