Human bio term 1 Flashcards
was is the structure and function of the cytoplasm
jelly like material
fills space between nucleus and membrane
75 - 90% water
cell organelles suspended in it
regulate osmotic pressure
was is the structure and function of the nucleus
largest organelle
oval of sphere shaped
nuclear membrane: double membrane, separates nucleus from cytoplasm
nuclear pore: gaps in the nuclear membrane, lets large molecules enter and leave the nucleus
nucleolus: inside nucleus, contains genetic material in DNA, plays a part in manufacturing proteins
was is the structure and function of the ribosomes
very small spherical organelles
site of protein synthesis
either attached to endoplasmic reticulum or free floating in cytoplasm
was is the structure and function of the endoplasmic reticulum
pairs of parallel membranes extending from cell membrane to nucleus
channels are for storing or transporting molecules e.g. protein
provides surface for chemical reactions to take place
rough: ribosomes attached
smooth: no ribosomes
was is the structure and function of the Golgi body
flattened stacks
modifies and packages proteins
vesicles: small sacks of liquid containing proteins formed at the edges of the golgi body membrane
was is the structure and function of the lysosomes
small sphere containing digestive enzymes
can join with vesicles and break down material inside vesicles
remove/break down cell waste
what is the structure and function of the mitochondria
double membrane (outer and inner folded)
sausage shaped
some chemical reactions of cell respiration occur
provides energy available for cellular activities
breifly describe the cell centrioles
only appear during cell division
look like celery sticks in diagram
was is the structure and function of the cell membrane
controls/regulates movement of particles in & out of cell
regulates equilibrium in cell
phospholipid bilayer
phosphate head: hydrophilic (water loving), head faces cytoplasm and outside of cell (both mostly water)
glycerol neck connects to:
2 x fatty chain tails: hydrophobic (water hating), faces inward & not in direct contact with water
embedded between the phospholipids are proteins
list the different types of proteins embedded in the cell membrane
identity protein
receptor protein
carrier protein
channel protein
list some factors that movement across the cell membrane depends on
- concentration gradient: movement of particles from higher concentration will move to areas of lower concentration until it is evenly distributed
high - low = no energy
low - high = energy
- osmosis: diffusion of water
PASSIVE (with gradient and no energy) vs ACTIVE transport (against gradient and requires energy)
what are the different types of transport across the cell membrane
passive: no energy required
active: requires energy
explain simple diffusion
spreading out of particles from areas of high - low concentration until they’re evenly distributed down a concentration gradient
only occurs in gases and liquids
passive, no energy required
occurs across cell membrane
only lipid soluble substances
explain osmosis
movement/diffusion of water particles from areas of high to low concentration down a concentration gradient
through AQUAPORINS
water molecules can pass through both phospholipid bilayer and channel proteins.
explain the difference between facilitated diffusion and simple diffusion
facilitated: passive, with concentration gradient H-L, water soluble, requires assistance
e. g. glucose molecules
simple: passive, with concentration gradient H-L, lipid soluble, straight through membrane
e. g. O2, CO2
what are the 2 different types of passive transport
diffusion and osmosis
describe what active transport is
requires energy (ATP: adenosine triphosphate)
against concentration gradient L-H
example of active transport: vesicular transport
e.g. transporting ions
explain what vesicular transport is
movement of substances across the membrane in membranous sacks called vesicles
active process: energy is needed to form the vesicles
either
endocytosis: taking substances into the cell by vesicular transport. membrane forms around particle until completely enclosed. Vesicle pinches off and is suspended in the cytoplasm. In pinocytosis (liquids) or phagocytosis (solids)
exocytosis: contents of a vesicle inside the cell are passed to the outside. a vesicle migrates to the membrane and fuses with the membrane. contents of the vesicle are the pushed outside of the cell.
what are the 4 main types of tissue
muscular
epithelium
connective
nervous
describe the structure of epithelium tissue
cells are arranged in sheets
joined by small amount of intercellular matrix
rest on basement membrane
either:
simple epithelium: 1 layer
connective epithelium: several layers
describe the different types of simple epithelium tissue
squamous
cuboidal
columnar
ciliated
describe compound epithelium tissue
several layers of cells
cells become flatter and more scale like closer to the surface
cells lose their living contents in the skin
found in lining of mouth, pharynx and oesophagus
what is the function of epithelium tissue
lines internal organs and cavities
protects underlying cells from injury, harmful chemicals, bacteria or drying
absorption
secretes waste
sensation
describe connective tissue
binds parts of the body together
provides support
found in: rib cage, ears, and joints between bones
name the different types of connective tissue
areolar
adipose
cartilage
bone
describe cuboidal epithelium tissue
cells are nearly cube shaped
found in the kidney
describe columnar epithelium tissue
cells are column shaped
long axis at right angle to basement membrane
found in lining of stomach and intestines
describe squamous epithelium tissue
flattened and scale like
arranged edge to edge
found in lining of the mouth
describe ciliated epithelium tissue
short, actively waving threads called cilia are attached to cell edges
found in wall of trachea
describe areolar connective tissue
white and yellow fibres mixed together as well as other non fibrous ground substances
keeps internal organs in place and binds skin to deeper structures
found in:
under skin, binding it to muscle & surrounding various organs
describe adipose connective tissue
fatty tissue
few fibres and cells are swollen with fat droplets
protects organs close to it
emergency food reserve
found:
under skin, packed around internal organs
describe cartilage connective tissue
consists of tough matrix
cells are spread far apart; lots of cell matrix between them
cells continuously divide to multiply
each cell produce fresh matrix, spreading them further apart
found:
wall of trachea
describe bone connective tissue
very firm connective tissue
cells are separated by matrix of organic material
made up of groups of concentric layers of lamellae surrounding the Haversian canal (contains blood vessels and nerves)
in between lamellae lie small cavities, lacunae
lacunae is united with Haversian canal through canaliculi which run through the lamellae
describe muscular tissue
has the power of contraction
made up of fibres
3 types:
striped/skeletal/voluntary
unstriped/plain/involuntary
cardiac
describe striped/skeletal/voluntary muscular tissue
builds muscles under control of will
includes most ‘meat’ or ‘flesh’ of an animal
describe unstriped/plain/involuntary muscular tissue
builds muscle not under control of will
e.g. in the walls of gut and walls of blood vessels
capable of sustaining slow contractions even when separated from nervous system
sensitive to mechanical stimulation e.g. stretching
describe cardiac muscular tissue
only found in wall of heart
no sarcolemma and have faint cross striations
cells are not properly divides into seperate units, they branch and join with neighbours so a network is formed
describe nervous tissue
consists of nervous cells or neurones
has supporting tissue called neuroglia
found:
in brain
what is the role of an identity protein
determine which type of cell it is
what is the role of a receptor protein
fit with specific molecules to help carry them across the membrane
what is the role of a carrier protein
assist molecules moving across the membrane easily
what is the role of a channel protein
open and allow larger molecules to travel across membrane
