anat & phys chap 3

three parts of cell theory

1. cells are the basic structural and functional unit of all living things

2. Activity of an organism depends on the activity within its cells

3. The biochemical activities are dictated by the relative number of subcellular structures

4. Reproduction

3 parts of a cell

1. nucleus

2. cytoplasm

3. plasma membrane

three parts of the nucleus

1. nuclear envelope

2. nucleolus

3. chromatin

What are DNA instructions mostly used to build

proteins

nuclear envelope function

has pores to allow substances to pass in and out

nucleolus function

where ribosomes are assembled

Where do most ribosomes go to after they are made in the nucleolus

cytoplasm

what is chromatin

DNA combined with proteins

what does chromatin do during cell division

it condenses and forms chromosones

what is the plasma membrane

barrier that surrounds cell contents

why is it called the fluid mosaic modal

The bilayer is always on-going and there are lots of parts

why is water attracted and repealed by the bilayer

The phosphate heads are polar and hydrophillic, drawing in the water, and the lipids are nonpolar and repell the water away

What do membrane proteins do

serve as enzymes (chemical messengers, building sites, and are involved in transport of necessary materials)

channel proteins

pores that allows water and water-soluble molecules through

carrier proteins

bind to a substance in order to help move it in or out

glycoproteins

Sugars bonded onto protein that determine blood type, bind to bacteria and viruses and are involved in cell-cell recognition

what are membrane junctions made of

protein

tight junctions

bind together like a zipper into leak-proof sheets

where in the body would tight junctions be necessary

in the digestive system to prevent acid and digestive enzymes from seeping into the blood stream

desmosomes

button like connections by fine protein filaments that prevent cells being pulled apart

where would desmosomes be necessary in the body

skin cells

gap junctions

hollow cylinders composed of special proteins that connect cells in order to communicate with one another

where would gap junctions be necessary in the body

the cardiac muscles that need to send electrons efficiently to one another in order to create the electrical charge to keep the heart pumping

cytoplasm

jell-like liquid inside the cell that suspends organelles

mitocondria

contain special enzymes that carry out cellular respiration in order to produce ATP

why would some cells have more mitochondria than others

some cells need more energy to function

what is the only organelle that contains it own DNA

mitochondria

ribosomes

made of rRNA that manufactures proteins (protein synthesis)

where do ribosomes hang out in the cell

either free floating or attached to the rough er

rough er

system of fluid filled tubules that fold and twist in the cytoplasm where ribosomes attach to

smooth er

system of fluid filled tubules that help with lipid metabolism and detoxification

golgi apparatus

modifies, packages, and transports proteins

how does the golgi apparatus package proteins

they put a membrane around it

lysosomes

formed by ribosomes that contain powerful digestive enzymes to breakdown old organelles and foreign substances of the cell

protein making process (3 steps)

1. transcription (DNA —>RNA)

2. gets picked up by a ribosome

3. assemble amino acids

what do peroxisomes do

use molecular O2 to detoxify poisons and create “free radicals” that’s then converted into water

cytoskeleton

a network of protein stuctures in order to support the cell’s shape and help in transporting materials

centrioles

rod-shape microtubes involved in generating spindle fibers during cell division

how do the spindle fibers help in cell division

they attach to the chromosomes and break them in half

cilia

moves substances across the cell surface (like crowd surfing)

flagella

propels the cell to move (like a tail)

microvilli

finger-like extensions of the cell membrane that increase its surface area for increased absorbtion

where would microvilli cells be necessary

in the small intestines to absorb nutrients

how many cells are there

over 200

fibroblast

make connective tissue that connects body parts

what is an erythrocytes (RBCs) shape and why

a concave disk shape in order to increase surface area (hemoglobin) so it can hold and carry more oxygen

epithelial cells

cover and line body organs and are packed together in sheets connected by tight junctions in order to resist tearing

what cells move organs and body parts and how

smooth and skeletal through contractile filaments

fat cells

store nutrients in the form of lipids

what are macrophages and how do they function

cells that fight disease by consuming foreign substances and release lysosomes to digest it

nerve cells

cells that gather info and control body functions

two reproductive cells

oocytes (female eggs) sperm (male)

how does sperm function

has a large flagellum built for swimming to the egg

four types of tissue

epithelial, nervous, muscle, connective

three types of epithelial tissue

simple, stratified, glandular

epithelial tissue function (4)

protect, absorb, filter, and secrete (dispose)

simple epithelia

very thin that lines many organs

stratified epithelia

2 or more layers made for protection (skin)

glandular epithelia

involved in secretion, specifically endocrine glands

four types of connective tissue

bone, cartilage, dense connective, loose connective

bone connective tissue

composed of osteocytes: calcium salts and collagen fibers to protect and support

cartilage connective tissue

composed of chondrocytes that’s more flexible than bone by still protects and supports

dense connective tissue (thick but stretchy)

composed of collagen and fibroblasts to form tendons and ligaments

two types of loose connective tissue

adipose and blood

adipose function

energy storage, insulation, and cushioning

why is blood considered a tissue

is composed of at least 2 cells

three types of muscle tissue

skeletal, cardiac, and smooth

skeletal muscle tissue

voluntary muscles with cells that are elongated for contraction

cardiac muscle tissue

involuntary muscle with gap junctions to allow ions to pass quickly

smooth muscle tissue

involuntary muscle of hollow organs with much slower contractions and no striations

neurons

receive and conduct electrochemical impulses in order to sense the world around us

neuroglia

insulate, support, and protect the neurons

cancer (in basic terms)

cells don’t know when / how to stop dividing because the genes responsible for regulating cell division are damaged

carcinogens

known causes for cancer (asbestos, nicotine, uv radiation)

benign

the tumor is in one area that is growing slowly and almost never kill the host

malignant

the tumor has spread to multiple parts of the body, growing quickly, and can be fatal

three parts where nervous tissue is found

nerves, spinal cord, brain

solution

homogeneous mixture of two or more components

solvent

substance present in the largest amount and does the dissolving

solute

substance present in smaller amounts and gets dissolved

intracellular fluid

solution within the cell that contains small amounts of gases, nutrients, and salts

interstitial fluid

fluid outside of the cell that contains substances that the cells need to extract in order to maintain homeostasis

selective permeability

a barrier (cell membrane) that allows only certain substances to enter and exit

diffusion

process where substances move from low concentration to high as a result of kinetic energy

concentration gradient

the difference in concentration of a solute between two areas (“moving down / up the gradient”)

facilitated diffusion

protein channel is used to transport large / insoluble material in and out of the cell

osmosis

process of moving water across the membrane

why does osmosis need to occur

to either balance the concentration of the solute or go to the area with lower water concentration