Anatomy & Physiology Ch. 3 (Cellular Structure)

Front 1

3 main parts of a cell

Back 1

plasma membrane
cytoplasm
nucleus

Front 2

plasma membrane consists of:

Back 2

lipid bilayer
proteins

Front 3

cytoplasm consists of:

Back 3

cytosol
organelles

Front 4

nucleus contains

Back 4

chromatin
nucleolus

Front 5

function of lipid bilayer

Back 5

the framework of the plasma membrane

Front 6

types of lipid molecules in the lipid bilayer

Back 6

phospholipids - 75%
cholestrol - 20%
glycolipids - 5%

Front 7

structure and function of phospholipids

Back 7

amphipathic
non-polar tail/ hydrophobic
polar head/ hydropilic

Front 8

function of cholestrol

Back 8

firms up cell channels - supports membrane structure

Front 9

function of glycolipids

Back 9

sugary coating (glycocalyx)
acts like a molecular signature (cell identity marker)
to enable MHC (major histocompatability)

Front 10

function of plasma membrane

Back 10

flexible, sturdy barrier that surrounds and contains the cytoplasm of the cell

Front 11

fluid mosaic model

Back 11

descriptive term for the structure of the plasma membrane - constantly in motion; consisting of a variety of small parts

Front 12

2 types of membrane proteins

Back 12

integral (transmembrane)
peripheral

Front 13

integral membrane proteins

Back 13

amphipahtic (phobic & philic)
extends through the lipid bilayers (transmembrane)

Front 14

peripheral membrane proteins

Back 14

either on the inner or outer membrane (hydrophilic)

Front 15

functions of plasma membrane proteins

Back 15

1) ion channel
2) transporter
3) receptor
4) enzyme
5) linkers
6) cell identity marker

Front 16

ion channel

Back 16

integral protein
that forms a water filled pore

Front 17

transporter

Back 17

integral protein
tube shaped -
binds to a specific substance
then changes shape to move & eject the substance across memebrane

Front 18

receptor proteins

Back 18

integral protein
recognizes annd binds to specific ligand molecules

Front 19

enzyme

Back 19

integral or peripheral protein
catalyzes reactions

Front 20

linkers

Back 20

integral or peripheral protein
aids in structural stability by
connecting to filaments inside or outside the membrane

Front 21

cell identity markers

Back 21

glycolipid
that identifies "foreigners"
MHC (major histocompatability) is one important class

Front 22

ligand

Back 22

a chemical substance that binds to a specific receptor

Front 23

Cytosol
(basic description)

Back 23

ICF
55% of total cell volume
75-90% of that volume is H₂O and dissolved and suspended components

Front 24

components in cytosol H₂O

Back 24

dissolved & suspended components:
ions, glucose, amino acids, proteins, lipids, ATP & waste
aggregations of organic molecules
such as: droplets containing triglycerides
glucogen granules

Front 25

cytosol function

Back 25

site of many chemical reactions required for cell's existence
[ie. catalyzes glycolysis:
10 chemical reactions that produce 2 molecules of ATP from one molecule of glucose]

Front 26

cytoskeleton

Back 26

network of 3 types of protein filaments that extend through the cytosol:
microfilaments
intermediate filaments
microtubules

Front 27

microfilaments

Back 27

composed of protein actin
thinnest element of cytoskeleton
prevalent at the periphery
has 2 functions

Front 28

2 functions of microfilaments

Back 28

1] generate movement:
muscle contraction
cell division
cell locomotion
2] mechanical support for basic strength and shape of cell by anchoring the cytoskeleton to integral plasma membrane proteins

2b] also support microvilli as a core of parrallel filaments

Front 29

intermediate filaments

Back 29

composed of several different proteins
found in parts of cells subject to mechanical stress

Front 30

2 functions of intermediate filaments

Back 30

1] help stabilize the position of organelles
2] helps attach cells to one another

Front 31

microtubules

Back 31

composed of protein tubulin
long, unbranched hollow tubes
begin in the centrosome and grow outward

Front 32

3 functions of microtubules

Back 32

1] help determine cell shape
2] function in the movement of chromosomes (chromatid pairs) during cell division
3] function in the movement of secretory vesicles and specialized cell projections such as cilia and flagella

Front 33

centrosome

Back 33

located near the nucleus
consists of two centrioles
surrounded by pericentriolar material

Front 34

centrioles

Back 34

nine clusters of three microtubules each (triplets)-
arranged in a cylindrical structure
two of these compose the basis of a centrosome

Front 35

pericentriolar material

Back 35

surrounds the centrioles
contains hundred of ring shaped complexes compose of the protein tubulin
center for growth of the mitotic spindle

Front 36

cilia

Back 36

short, hairlike motile projections that extend from the surface of the cell
composed of 10 fused doublets of microtubules anchored to a basal body just below the surface of the plasma membrane
facilitate steady movement of fluid along cell's surface

Front 37

flagellum

Back 37

similar in structure to cilia but are typically much longer
they usually move an entire cell
only human flagella= sperm

Front 38

ribosomes

Back 38

site of protein synthesis
high content of one type of ribonucleic acid - ribosomal RNA (mRNA)
also contains 50+ proteins
their structure is of 2 subunits - large subunit & small subunit
lg. & sm. subunits are made separately,
then come together in the cytoplasm

Front 39

attached ribosomes

Back 39

attached to the outer surface of the nucleus and rough ER they synthesize
organelle proteins
membrane proteins
secretory proteins

Front 40

"free" unattached ribosomes

Back 40

synthesize protein used in the cytosol

Front 41

ribosomes within mitochondria

Back 41

synthesize mitochondrial proteins

Front 42

Endoplasmic reticulum

[plasmic=cytoplasm; reticulum=network]

Back 42

network of membranes that extend from the nuclear envelope throughout the cytoplasm
>50% of membranous surfaces within most cell's cytoplasm
2 kinds - rough ER
smooth ER

Front 43

Rough endoplasmic reticulum

Back 43

continuous with the nuclear envelope
folded into a series of flattened sacs
proteins synthesized by attached ribosomes
enter rough ER spaces for processing and sorting

Front 44

Smooth endoplasmic reticulum

Back 44

extends from the rough ER to form a network of membrane tubules
does not have ribosomes on it's surfaces
contains unique enzymes and synthesizes fatty acids & steroids
functionally more diverse than rough ER
enzymes help detoxify potentially harmful substances
helps "free" certain glucose to enter the bloodstream
ions trigger muscle contractions

Front 45

Golgi complex

Back 45

1st step in the protein transport process
3-20 cisternae:
convex entry or cisface cisterna
concave exit or transface cisterna
medial cisterna
each type of cisterna has different enzymes to modify, sort & package proteins for transport

Front 46

Golgi complex
processing & packaging of proteins

Back 46

1] transport vesicles from rough ER fuse to cisface & release proteins into the lumen (space)

2] proteins move into the medial cisternae & are processed

3] after processing, proteins leave the transface in:
secretory vesicles for exocytosis
membrane vesicles for incorporation into the plasma membrane
transport vesicles for other intracellular destinations, such as lysosomes

Front 47

Lysosomes

[lyso=dissolving; somes=bodies]

Back 47

membrane enclosed vesicles that form from the Golgi complex
contains powerful digestive enzymes
interior has acidic Ph5 for optimum enzyme function

Front 48

lysosome function

Back 48

digest substances that enter via endocytosis and
transport final products of digestion into cytosol
carry out autophagy
carry out autolysis
carry out extracellular digestion (sperm head)

Front 49

peroxisomes

Back 49

similar to lysosomes but smaller
contain several oxidases which oxidize and detoxify
abundant in the liver

also contains catalase which decomposes hydrogen peroxide a
byproduct of oxidation

Front 50

proteasomes

Back 50

tiny, barrel-shaped structures

continuously destroy unneeded, damaged, or faulty proteins
with myriad proteases
which chop up proteins into small peptides
so they can be broken down into amino acids and recycled

Front 51

mitochondria

Back 51

self-replicating, containing it's own DNA
this "powerhouse" of the cell generates ATP through aerobic cellular respiration
consists of : outer mitochondrial membrane,
small fluid-filled space then
the inner mitochondrial membrane which contains
a series of folds called cristae [increases surface area for chemical reactions]
enclosed by the inner mitochondrial membrane is the matrix
mitochondrial genes are inherited only from your mother

Front 52

nucleus

Back 52

spherical or oval shaped structure
prominent feature of most cells
contains most of the cell's genes
control cellular structure
directs cellular activity
nuclear envelope
chromatin
nucleolus

Front 53

nuclear envelope

Back 53

double membrane that separates the nucleus from the cytoplasm
both layers are lipid bilayers
opening called nuclear pores extend through the envelope

Front 54

nucleoli

Back 54

produces ribosomes
disperse and disappear during cell division
reorganize once new cell is formed

Front 55

chromatin

Back 55

complex of DNA, proteins and some RNA
beads-on-a-string structure
each nucleosome "bead" has a core of eight proteins called
histones with double-stranded DNA wrapped around twice
holding the nucleososmes together is linker DNA

Front 56

chromatid

Back 56

replicated DNA forms a pair of chromatids
during cell division a pair of chromatids constitutes a chromosome

Front 57

gene expression

Back 57

gene's DNA is expressed as a template for the synthesis of a specific protein

Front 58

genetic code

Back 58

the set of rules that relate the base triplet sequence of DNA to the corresponding codons of RNA

Front 59

base triplet

Back 59

sets of three nucleotides where genetic information is stored

Front 60

intron

Back 60

does not code for parts of protein
(introverted)

Front 61

exon

Back 61

codes for parts of protein
(expressive)