Cells and Tissues Flashcards
What is the function of cell/s?
To carry out all chemical activities needed to
sustain life
most cells are composed 4 main elements:
carbon,
hydrogen,
oxygen,
nitrogen
How many % of water is a cell consist of?
60% consisting of water
T or F
cells are the building block of all living things
TRUE
study of cell, also called cell biology
Cytology:
groups of cells that are similar in structure and function
Tissues
all cells share general structures, and cells are organized into three main regions
nucleus
cytoplasm
plasma membrane
It is a barrier for cell contents, forms the cell’s flexible outer surface separating the external and internal environment
Plasma Membrane
A selective barrier that regulates the flow of materials into and out of a cell, plays a key role in communication among cells
and between cells and their external environment
Plasma Membrane
a structural model called the__________, acts as a barrier to the entry or exit of charged or polar substances
structural model called the fluid mosaic model
back-to-back layers made up of 3 lipid molecules: phospholipids (75%), cholesterol (20%), and glycolipids (5%)
Double Phospholipid Layer (lipid bilayer)
T or F
The bilayer arrangement occurs because the amino acids are amphipathic, which means they have both polar and nonpolar part
FALSE
The bilayer arrangement occurs because the lipids are amphipathic, which means they have both polar and nonpolar part
What is the part that attracts water?
(water-loving polar head)
hydrophilic heads
What is the part that repels water, no charged cells, (water-fearing nonpolar head), makes the plasma membrane permeable, two long fatty acid “tails”
hydrophobic tails
T or F
hydrophilic heads face outwards, on either side – cytosol and ECF
hydrophobic tails, point toward one another forming a nonpolar, hydrophobic region in the membrane’s interior
TRUE
Other materials found in plasma membrane (3)
protein
cholesterol
glycoproteins
It is responsible for being the receptor for hormones, and serves as transporter or carriers
Cholesterol
The part that extend into or through the lipid bilayer and are firmly embedded in it; amphipathic
Integral Proteins:
T of F
Specialized proteins: mostly integral proteins, they span the entire lipid bilayer and protrude into both cytosol and ECF
FASLE
Transmembrane proteins: mostly integral proteins, they span the entire lipid bilayer and protrude into both cytosol and ECF
Proteins with carbohydrate groups attached to the ends that protrude into the ECF
Glycoproteins
An extensive sugary coat formed by the carbohydrate portions of glycolipids and glycoproteins
Glycocalyx
T or F
Peripheral Proteins: not firmly attached in the membrane; attached to the polar heads of membrane lipids or to integral proteins at the inner or outer surface membrane
TRUE
Functions of Membrane Proteins
Some integral proteins form ion channels, pores or holes that specific ions can flow through to get into or out of the cell
o Other integral proteins act as carriers or transporters
o Integral proteins called receptors serve as cellular recognition sites. A specific molecule that binds to a receptor is called a ligand
o Some integral proteins are enzymes that catalyze specific chemical reactions at the inside or outside surface of the cell
o Integral proteins may also serve as linkers that anchor proteins in the plasma membranes of neighboring cells or to protein filaments inside and outside the cell
finger-like projections that increase surface area for absorption
Microvilli
Member junctions
tight junctions:
desmosomes:
gap junctions:
adherens junctions:
hemidesmosomes:
anchor cells not to each other but to the basement membrane
hemidesmosomes:
contains plaque that attaches both to membrane proteins and to microfilaments of the cytoskeleton
adherens junctions:
communicating junctions, responsible for molecules that can travel from one cell to another
gap junctions:
impermeable, does not allow passage of ions or enzymes, binds cells together
tight junctions:
It consists of all the material outside the nucleus
and inside the plasma membrane
Cytoplasm
fluid that suspends other elements
▪ also called intracellular fluid
▪ consists of water, dissolved solutes, and suspended particles
Cytosol
metabolic machinery of the cell
Organelles
non-functioning units inside the cells that are considered to be chemical substances (nutrients)
Inclusions
Part of a cell that is
made of protein and RNA
* sites of protein synthesis
* found at two locations:
Ribosomes
Ribosomes can be found where?
found at two locations:
i. free in the cytoplasm
ii. attached to rough endoplasmic reticulum (ER)
Part of the cell where
It is studded with ribosomes
ii. site where building materials of cellular membrane are formed
iii. mainly for protein synthesis
Rough ER
functions in cholesterol synthesis and breakdown, fat metabolism, and detoxify drugs
Smooth ER
Function of the Golgi Apparatus
modifies and packages proteins
contain enzymes that digest non-usable materials within the cell
* found in WBCs
* contains dead materials
Lysosomes
T or F
Lysosomes can be found in RBCs
FALSE
Lysosomes can be found in WBCs
- membranous sacs of oxidase enzymes
- detoxify harmful substances
- breakdown free radicals (highly reactive chemicals)
- free radicals are converted to hydrogen peroxide and then to water
- replicate by pinching in half
Peroxisomes
change in shape continuously
* carry out reactions where oxygen is used to break down food
Mitochondria
provides ATP for cellular energy
Mitochondria
provides ATP for cellular energy
Mitochondria
network of protein structures that extend throughout the cytoplasm
Cytoskeleton
Cytoskeleton provides what?
provides the cell with an internal framework
thin, rod-like structures near the cell’s periphery
ii. they provide support and shape to the cell
iii. they are also involved in muscle contraction, cell division, and cell locomotion
microfilaments
larger and provide structural reinforcement in some cells and
assist in contraction in others
intermediate filaments
large, long, hollow tubes that provide support and shape for cells
ii. provide framework for cilia and flagella, and are involved in moving chromosome during cell division
microtubules
T or F
Centrioles are cube shape bodies made of microtubules
FAlSE
Centrioles are rod shape bodies made of microtubules
direct formation of mitotic spindle during cell division
Centrioles
T or F
Cellular projections not found in all cells
TRUE
move materials across the cell surface; the cilia will not move but the materials around will; move fluids along a cell’s surface; mainly found in respiratory tract
cilia
propels the cell; moves an entire cell; forward motion; sperm cell
flagellum
T or F
Neurons control center of the cell
FALSE
Nucleus control center of the cell
contains the DNA
o inside it, the chromosome (a single molecule of DNA) contains thousands of hereditary units called genes
Nucleus
control most aspects of cellular
structure and function
Genes
barrier of nucleus
consists of a double phospholipid membrane
Nuclear Membrane
also called “nuclear envelope”
Nuclear Membrane
also called “nuclear envelope”
Nuclear Membrane
contain nuclear pores that allow for exchange of material with the rest of the cells
Nuclear Membrane
sites of ribosome production
* ribosomes then migrate to the cytoplasm through nuclear pores
Nucleoli
T or F
Chromatin is composed of RNA and protein
FALSE
Chromatin is composed of DNA and protein
Term for
Cells that connect body parts
fibroblast
▪ RBC (Erythrocyte); contains no nucleus
Cells that cover and line body organs
Epithelial cell
Cells that move organs and body parts
▪ skeletal muscle cell
▪ smooth muscle cell (mainly found in internal organs)
Cell that stores nutrients
▪ fat cell
Cell that fights disease
▪ macrophage cell
Cell that gathers information and controls body functions
▪ nerve cell
Cells of Reproduction
▪ sperm and egg (ovum) cell
T or F
Transport across the Plasma Membrane
ICF (Intracellular fluid) – fluid in body cells
ECF (extracellular fluid) – fluid outside the cells
Interstitial fluid – ECF between cells in tissues
TRUE
T or F
solvent – dissolving medium (water, chemicals that can dissolve)
▪ solutes – components in smaller quantities (sodium)
TRUE
A type of transport that uses no energy required, toward the concentration gradient (hi-low)
o substance moves down to its concentration
Passive transport
Passive transport includes
simple diffusion, facilitated diffusion, osmosis
A type of Transport that need metabolic energy
o used to drive the substance “uphill” against the concentration gradient
o primary and secondary; also through membrane sacs or vesicles
Active Transport
A type of Transport that need metabolic energy
o used to drive the substance “uphill” against the concentration gradient
o primary and secondary; also through membrane sacs or vesicles
Active Transport
RNA that transfers appropriate amino acids to the ribosome for building the protein
tRNA
RNA that helps forms the ribosomes where proteins are built
ribosomal RNA (rRNA)
RNA that carries the instructions for building a protein from the nucleus to the ribosome
messenger RNA (mRNA)
RNA that carries the instructions for building a protein from the nucleus to the ribosome
messenger RNA (mRNA)
Cell life cycle
o Two major periods:
Interphase:
Cell division:
Phase where cell grows, cell carries on metabolic processes, no cell division occurs; the cell carries out normal metabolic activity and growth, chromatin is present, DNA replication occurs
Interphase:
Phase where cell replicates itself, function is to produce cell for repair processes and growth
Cell division
division of cytoplasm, begins when mitosis near completion, 2 daughter cells
Cytokinesis:
T or F
the reproductive cell division that occurs in the gonads, produces gametes in which the number of chromosomes is reduced 3 times
FALSER
the reproductive cell division that occurs in the gonads, produces gametes in which the number of chromosomes is reduced by half
Term for cells that are specialized for particular functions
Body Tissues
4 primary types of Tissues:
epithelium,
connective,
nervous,
muscle
Tissues that are found in body coverings, linings, and glandular tissue
Epithelial tissues
Function of Epithelial tissues
protection,
absorption,
filtration,
secretion
T or F
squamous (Round),
cuboidal (cube shaped),
columnar (column-like)
FALSE
squamous (flattened),
cuboidal (cube shaped),
columnar (column-like)
number of cell layers:
simple (___ layer), stratified (______ layer)
number of cell layers:
simple (one layer), stratified (more than one layer)
found everywhere in the body
o include the most abundant and widely distributed tissues
Connective Tissue
Function of Connective Tissue
binds body tissues together,
supports the body,
provide protection
T or F
Blood is a connective tissue
TRUE
Epithelial Membranes includes:
Mucous Membrane
Serous Membrane
Cutaneous Membrane
Synovial Membrane
Muscular Tissues includes:
Skeletal
Cardiac
Smooth
