ANPS - Cell Structure

Intracellular

within the cell itself

Extracellular

outside the cell

Interstitial fluid

the fluid between the cells

Plasma membrane

the membrane that separates the cell from the interstitial fluid composed of most phospholipids and proteins

Phospholipid bilayer

a double layer of phospholipids composed of the lipids arranging themselves with the polar heads facing out and their nonpolar tails facing in

Integral membrane protein

transmembrane proteins embedded through the membrane

Peripheral membrane protein

proteins bound to inner or outer surface of the membrane

Transport protein

proteins that allow molecules to go through the membrane that would otherwise not be able to pass through the lipid bilayer

Receptor protein

bind chemical signals from other cells and trigger a response

Anchoring protein

ties the membrane to the cytoskeleton and to extracellular molecules

Membrane enzyme

catalyze reactions at the cell surface

Cell-Cell Junction protein

allow cells to bind with neighboring cells

Recognition/Identity protein

allow cells to be identified by other cells

Glycocalyx

a carbohydrate associated with the membrane

Fluid-Mosaic membrane model

the moveable nature of the membrane due to its composition

Permeability

the ease with which substances can cross the cell membrane

Impermeable

nothing can get through the membrane

Freely permeable

anything can pass through the barrier

Selectively permeable

only allows certain particles through

Passive process

do not require energy expendidture to move something through the membrane

Active process

require ATP in order to move something through the membrane

Osmosis

the diffusion of water

Isotonic

solute/water concentration is the same on the inside of the cell as it is in the outer fluid (doesn't have to be the same salts)

Hypertonic

more solutes in the outer fluid, causing water inside the cell to travel out and the cell shrivels

Hypotonic

more solutes in the inside of the cell, causing water to move from the outside to the inside of the cell causing it to swell

Functions of plasma membrane

physical isolation from environment, selective exchange with environment, maintain chemical gradient, communication with environment

Cholesterol

type of lipid, makes phospholipid bilayer more rigid

Glycocalyx

carbs on the surface of the membrane, help anchor cells to extracellular materials, bind extracellular molecules

aquaporins

protein channels that only allow water through the plasma membrane

Cytoplasm

composed of intracellular fluid and organelles

Membranous Organelles

have a membrane

Nonmembranous Organelles

not enclosed in a phospholipid membrane

Double membrane

a membrane enclosed by another membrane

Nucleus

the only organelle that can be seen with a light microscope, has nucleoplasm/genome/proteins

Nucleoplasm

the material containing the nucleus

Nucleolus

active areas within DNA, dark cluster or spot, indicative of active protein synthesis

Chromatin

the uncoiled form of DNA found when the cell is active

Chromosome

the tightly packed form of DNA when the cell is getting ready to replicate

Histone protein

proteins in the nucleus that organize the DNA

Gene

small segment on a chromosome which codes for a unique protein

Nucleotide

building block of DNA

Transcription

a copy of a gene is produced in the nucleus (mRNA), RNA polymerase and RNA nucleotides are needed

Translation

mRNA is read by a ribosome and a protein is produced based on the sequence of nucleotides in the mRNA, mRNA ribosomes and amino acids (tRNA) are needed

Nuclear Pore

holes in the nuclear membrane; how mRNA leaves the nucleus

Complimentary base pairing

A and T(U) C and G

Messenger RNA (mRNA)

carries the code to make protein from the DNA into the cytoplasm

Ribosomal RNA (rRNA)

combines with proteins to form the ribosome organelle

Transfer RNA (tRNA)

cytoplasmic RNA strand that binds an amino acid at one end and carries it to the ribosome during protein synthesis; different tRNA's have different amino acids

Ribosome

non membranous organelle, site of protein synthesis, free floating or fixed to the ER

Free ribosome

floating in the cytoplasm (protein synthesis always starts on a free ribosome)

Fixed ribosome

bound to the rough ER (when the proteins need a membrane)

Endoplasmic reticulum

intracellular membranes involved in synthesis, storage, transportation and detoxification

Cisternae

spaces inside the ER separate from cytoplasm

Rough Endoplasmic Reticulum

used in protein synthesis; rough because ribosomes cover the outside

Smooth Endoplasmic Reticulum

involved in lipid synthesis

Golgi Apparatus

modifies, packages, and directs membrane-associated proteins to their final destination

Secretory vesicle

a vesicle used to transport proteins to the plasma membrane and released by exocytosis

Lysosome

vesicles containing digestive material

Mitochondria

makes energy for the cell

cristae

the highly folded inner membrane of the mitochondria that's loaded with proteins

Cytoskeleton

structural support and trafficking within the cell

Microfilaments

smallest, weblike arrangement inside the plasma membrane (help in cell movement and support)

Intermediate filaments

strong, resist mechanical stress to cell, stabilize the position of organelles within cytoplasm

Microtubules

largest, long and hollow, anchored in centrosome; provide strength and rigidity to cell, create movement of cell, provide chromosome movement during cell division and rapid transport

Somatic cells

body cells, comprising our organs and tissues

Gametes

sperm and egg cells

Mitosis

the equal division of the parent cell into 2 daughter cells

Meiosis

gamete cell division

Cell differentiation

the process that turns identical cells into specialized cells (liver cells vs neurons vs epithelial cells)

Pluripotent

early embryonic stem cells can create many different types of cells

Stem Cells

cells whose only job is to divide and create new cells

Interphase

stage of growth and division for the cell

Daughter cells

the new cells created during mitosis that are genetically identical (or different) from the original cell they were made from

G0

when cells are fully mature and stop dividing

DNA polymerase

matches up DNA nucleotides to the parent strand building a new double strand

Sister/Twin chromatids

the form of the chromosomes after they have replicated (one old strand and one new strand)

Centromere

the region of a chromosome where the microtubules of the spindle attach

Centriole

organize microtubules before and during the mitotic phase

Mitotic spindle (microtubules)

fibers that deliver the duplicated genomes to their respective poles during anaphase

Cell Cycle Checkpoints

ways in which the cell makes sure it is healthy enough to divide at each point in its cell life

Protooncogenes

genes whose normal protein products stimulate the cell cycle if the environment is correct

Oncogenes

mutated protooncogenes that continue to drive cell division even with the mutations (causing cancer)

Tumor Suppressor genes

genes whose normal protein products repress cell division by maintaining checkpoints

Carcinogens

substances that cause cancer

Carcinoma

cancer of epithelial cell origin (90%)

Leukemia/Lymphoma

cancers of blood lines (8%)

Sarcoma

solid tumor of other connective tissue (rare)

Benign

tumor remains confined to its original location and does not invade surrounding tissue

Malignant

invades adjacent tissue and spreads to other parts of the body

Metastasis

the process of a tumor spreading from its original location

G1 phase

synthesis of proteins and RNA for maintenance activities, synthesize proteins for S phase, duplicate organelles, growth

S phase

replication of DNA, sister chromatids formed, centrioles duplicate

G2 phase

protein synthesis to prepare for mitosis, more cell growth

Prophase

genome condenses into chromosomes, centrioles move to opposite poles, mitotic spindle forms, nuclear membrane dissolves

Metaphase

sister chromatids align at the center of the cell

Anaphase

microtubules pull apart sister chromatids

Telophase

microtubule spindle breaks apart, nuclear membrane forms around new genome, chromatids unwind into chromatin

Cytokinesis

actin network pulls membrane into a cleavage furrow at the midline, furrow grows until the cytoplasm splits

G1 checkpoint

cell size is adequate, nutrient availability is good, growth factors are present

G2 checkpoint

cell size is adequate, chromosome replication is complete