The Cells: The Raw Materials and Building Blocks

what are cells?

the fundamental units of all living things known as “building blocks” of our body that work together to allow for proper functioning of processes necessary for life

what are the sizes of cells?

1/3 to 1/13 the size of the dot on this exclamation point !

what is the longest cell and the length?

nerve cells can be two feet in length or longer

what are the shapes of cells?

flat, round, threadlike, or irregularly shaped

what is the med term for muscle cell?

myofibril

what is the function of myofibril?

form muscles for movement/maintaining position of body parts

T or F: you are born with all the muscle cells that you’ll ever get

true

what is the med term for nerve cell?

neuron

what are the functions of neurons?

to carry impulses to and from the brain

what is the med term for red blood cells?

erythrocytes

what is the function of erythrocytes?

move oxygen and carbon dioxide to and from tissues

what is the lifespan of a RBC?

120 days

what is the med term for white blood cells?

leukocytes

how much main types of WBCs are there

5

what do almost all human cells posses?

a nucleus (except RBCs), organelles, cytoplasm, and a cell membrane

what is the cell membrane also known as and why?

the plasma membrane since it surrounds the cytoplasm of the cell

what is a cytoplasm?

a defined boundary that possesses a definite sharp and actually holds the cell contents together

what do cell membranes act as and what is their responsibiity?

a protective covering thats responsible for allowing materials into and out of the cell

why is the membrane known as a selectively permeable or semipermeable membrane?

it allows certain things into or out of the cell

what is the cell membrane composed off?

mainly lipids and proteins with some carbohydrates and contain abundant amounts of cholesterol

what is the bulk of the cell membrane composed of?

a double layer of phospholipids, oriented tail to tail (hydrophilic head and hydrophobic tails)

what does the bilayer prevent in the cell membrane?

hydrophilic molecules from passing through membrane while hydrophobic molecules can pass rather easily

how do membrane proteins also contribute to the selective permeability of the cell membrane?

act as channels so substances can pass across the membrane or can carry substances across the membrane

what are proteins also called and why?

histocompatibility markers since they are compatibility markers

how thick is the cell membrane?

3/10,000,000 of an inch

what are the two transport methods in the cell?

passive transport and active transport

what is passive transport?

moving substances down its concentration gradient without requiring extra forms or energy

what is active transport?

substances are being transported up their gradient while needing addition energy through the process to make it happen

concentration gradient

the difference between the solute concentration of two solutions

what is passive transport further divided into?

osmosis, filtration, diffusion, and facilitated diffusion

what is diffusion?

when a solute travels from an area of higher concentration to an area of lesser concentration with the gradient

what is diffusion necessary for?

transporting oxygen from the lungs and into the blood, and transporting carbon dioxide from the blood to the lungs and eventually out into the air

what is osmosis?

water traveling through a selective permeable membrane when a concentration gradient is present so higher concentration of the solute is equal on both sides of the membrane

what is osmotic pressure?

ability of a substance to “pull” water toward an area of higher concentration of the solute (higher concentration = greater pressure)

what is the concept of tonicity?

impermeable solutes are allowed to travel through a special passageway in the cell membrane to balance solute concentration both inside and outside the cell

what is hypertonic solution?

when there is a greater impermeable solute concentration outside the cell than inside the cell (more solute; less water)

what is hypotonic solution?

when there is less impermeable solutes outside the cell than inside the cell (less solute; more water in solution)

what is isotonic solution?

when there are equal amounts of impermeable solutes inside the cell and outside the cell

what are some causes of hypertonic?

fever, certain meds, poorly controlled diabetes, kidney disease, watery diarrhea vomiting

what are some causes of hypotonic?

heart disease, kidney failure, drinking too much water, decreased salt intake, hyponatremia

cells love to be in an isotonic state and when something happens to make it unequal cells become ____

abnormal

what is filtration?

process in which water and substances in the blood are pushed through the pores of the glomerulus

what is the resulting fluid known as in filtration?

filtrate

what is it called when pressure is applied to force water and its dissolved materials across a membrane?

filtration

why is filtration considered a selective process?

pressure allows only solutes small enough to pass through channels and other openings in the membrane will filter across it

what is facilitated diffusion also known as?

carrier-mediated passive transport

what is facilitated diffusion?

when a protein channel helps a substance move across the membrane

why is facilitated diffusion still considered a passive transport?

since the substance is moving down its concentration gradient

which type of membrane transport is highly specific, may only carry one type of molecule, and is subject to saturation and inhibition?

facilitated diffusion

what are some types of facilitated diffusion?

ligand gated channels, voltage gated channels, mechanically gated

what is the categories active transport is broken into?

active transport pumps, endocytosis, exocytosis

what is active transport pumps also called?

carrier-mediated active transport

what is active transport pumps?

works the same way as facilitated diffusion but requires ATP to move a substance

why is energy needed for active transport pumps?

because the cell is trying to move a substance into an area that already has a high concentration of the substance

what is endocytosis?

ingestion of substances by cells

when is endocytosis utilized?

to intake liquid/solid particles when the substance is too large to diffuse across the cell membrane

what surrounds the substance and what does it form?

a cell membrane forming a vesicle which separates from the membrane and moves into the cell

what is phagocytosis?

if a solid substance is being tansported

what is pinocytosis?

if a liquid substance is being transported

what is exocytosis?

the transportation of substances out of the cell using vesicles

name the process of exocytosis

substance is made by the cell inside of the cell, substance gets surrounded by a membrane forming a vesicle, vesicle moves to the cell membrane, vesicle become a part of the cell membrane, vesicle expels its load out of the cell

what are the two basic types of exocytosis?

continuous and regulated

what is continuous exocytosis?

type of exocytosis present in all cells

what is regulated exocytosis?

a type of exocytosis specific to secretory cells that must first receive a signal

what are the components of a cell?

cytoplasm, nucleus, chromatin, nucleolus, ribosomes, centrosomes, centriole, mitochondria, endoplasmic reticulum, golgi apparatus, lyosomes, cytoskeleton, flagella, and cilia

what is the function of cytoplasm?

to provide a special environment for the internal parts of a cell to survive

what are cytoplasm made out of?

a watery solution of organic (proteins, carbohydrates, and lipids) and inorganic (minerals and gases) chemicals

what is the function of the nucleus?

to be the “brain of the cell” or control center to dictate the activities of the organelles in the cell

what is the nucleus surrounded by?

a double-walled nuclear membrane with large pores to allow certain materials to pass in and out

what is the purpose of chromatin?

to hold genetic material (DNA) found in the nucleus that eventually forms chromosomes which contain genes

what is the nucleolus made up of?

dense fibers found with the cell nucleus in a spherical body

what is the function of the nucleolus?

to synthesize RNA that forms ribosomes

what are ribosomes made up of?

RNA and proteins

what do ribosomes do?

assist in the production of enzymes and other proteins that are needed for cell repair and reproduction

where are ribosomes found?

on the endoplasmic reticulum and throughout the cytoplasm

what are centrosomes?

specialized region within the cell that contain centrioles

what do centrioles help in?

mitosis (cell division)

how do centrioles look and how are they found?

look tubular and usually found in pairs

what does the mitochondria look like and do?

a bean shaped organelle that makes ATP

what is the purpose of endoplasmic reticulum?

to transport materials within the cell, formed from folded membranes

what are the two distinct forms of endoplasmic reticulum?

rough ER and smooth ER

what does rough ER have and do?

has ribosomes on the surface and is responsible for the production or synthesis of protein

what does smooth ER have and do?

has no ribosomes on the surface and is responsible for synthesizing lipids and steroids

what is the purpose of the golgi apparatus?

to receive protein from the ER and further processes, prepare it for “shipping”, and transport it to the cell membrane (exocytosis)

what is the lysosomes and the purpose?

vesicles containing powerful hydrolytic enzymes that clean up intracellular debris and other waste while aiding in maintaining health by destroying unwanted bacteria via phagocytosis

what does the cytoskeleton do, provide, and allow?

networks of microtubules and interconnected filaments, providing shape to the cell, and allowing the cell and its content to be mobile

what is the flagella?

a whip-shaped tail that cause movement

where is the cilia and what does it look like?

short, microscopic, hairlike projections located on the outer surface of some cells

what is cellular reproduction?

the process of making a new cell

what is cell reproduction also known as?

cell division which is when one cell divides into two cells when it reproduces

what is asexual reproduction?

reproduction of a cell without the involvement of another cell which most cells are able to do

what are the two human cells?

eukaryotic cells and chromosomes

what do eukaryotic cells contain?

contain a nucleus usually with several chromosomes and cellular organelles

what do chromosomes contain?

all the instructions for cells which must have a complete set of 46 after reproduction and copied before the cell can divide

what is apoptosis?

the process of programed cell death

what is the life span of certain blood cells?

few hours

what is the life span of intestinal cells?

2-3 days

what is the life span of muscle cells?

can last for up to 15 years

what is the life span of nerve cells?

a lifetime

the total life of a eukaryotic cell consists of two phases, what are the two phases?

interphase and mitotic phase