BASIC COMPONENTS OF LIVING ORGANISMS Flashcards
description of cell membrane
found on the surface of animal cells and inside the cell wall of plant cells and prokaryotic cells, made of mainly lipids and protein
function of cell surface membrane
regulates the movement of substances into and out of the cell, also has receptor molecules which allow it to respond to chemicals like hormones
description of cell wall
rigid structure that surrounds plant cells, made of the carbohydrate cellulose
function of cell wall
supports plant cells and gives rigidity
description of nucleus
consist of nucleoplasm that contains chromatin, separated from cell contents by nuclear envelope with many openings called nuclear pores
function of the nucleus
control protein synthesis, metabolism, cell division, growth and differentiation, and store genetic information coded into DNA
structure and function of nucleolus
composed of RNA and protein and produces ribosomes
description of lysosome
round organelle surrounded by membrane with no clear internal structure
function of lysosome
contains digestive hydrolytic enzymes, which are kept separate from cell contents by a membrane, can be used to digest invading cells or break down worn out components of cell
description if ribosomes
small organelle that floats free or attached to RER, made of proteins and RNA
function if ribosomes
site of protein synthesis
describe the structure and function of the rough endoplasmic reticulum
system of membranes that is continuous with the nucleus, with ribosomes on the outer surface. Site of synthesis and transportation of proteins and glycoproteins
what is the structure and function of the smooth endoplasmic reticulum
system of membranes with no ribosomes on the outer surface. Site of synthesis, storage and transportation, and carbohydrates
4 functions of the golgi apparatus
- produces secretory enzymes and carbohydrates
- stores and modifies proteins and triglycerides
- forms vesicles for transporting proteins/triglycerides
- forms lysosomes
description of vesicle
small fluid filled sac in the cytoplasm, surrounded by a membrane
function of vesicles
transports substances in or out of the cell or between organelles, formed at cell surface, golgi and endoplasmic reticulum
description of mitochondrion
oval shaped with a double membrane, inner one is folded to form structures called cristae, inside is the matrix which contains enzymes involved in respiration
function of mitochondrion
site of aerobic respiration where ATP is produced
description of chloroplasts
found in plant cells, double membrane which has membranes inside called thylakoid membranes which are stacked up in some parts to form grana which are linked together by lamellae
function of chloroplasts
site where photosynthesis takes place, some happen in the grana and other parts in the stroma
description of centrioles
hollow cylinders made of microtubules found in some animal cells but only some plant cells
function of centrioles
involved with the separation of chromosomes during cell division
description of cilia
small hair like structures found on the surface membrane of some animal cells, 9+2 formation
function if cilia
microtubules allow the cilia to move, which is used by the cell to transport substances along the cell surface
description of flagellum
like cilia but longer stick out from the cell surface
function of flagellum
microtubules contract to make the flagellum move, which is used to propel the cell forward
what are the first steps to protein production
ribosomes on RER make proteins that are excreted or attached to cell membranes, and free ribosomes make proteins that stay in the cytoplasm
what happens to proteins produced at the rough ER
folded and processed in rough ER and then transported to the golgi apparatus in vesicles
what happens to the proteins at the golgi apparatus and after
further processing, then enter vesicles to be transported around the cell
what are the three components of the cytoskeleton
microfilaments made of actin, microtubules made of tubulin and intermediate filaments
what are the four functions of the cytoskeleton
to give the cell shape and stability, move organelles around the cell, allow cell movement and contraction, and enable movement of chromosomes during nuclear division
what are some key differences between eukaryotic ans prokaryotic cells
pro - DNA is circular, no nucleus, cell wall made of polysaccharide, no membrane bound organelles, flagellum arranged in helix, small ribosomes
euk - DNA is linear, nucleus, cell wall made of cellulose or chitin, membrane bound organelles, flagella made of microtubules, larger ribosomes
how to calculate magnification
image size / object size
describe light microscopes
use light, lower resolution, max magnification is X 1500
describe Laser Scanning Conofocal Microscopes
use laser beams, specimen tagged with fluorescent dye, light focused through a pinhole onto a detector which is hooked up to a computer to give an image, 3D, cleare image, can be used on objects at different depths in thick specimens
describe an electron microscope
use electrons to give an image, higher resolution than light microscopes, two kinds - TEM and SEM, TEM high resolution, although can only be used on thin specimens, SEM can be 3d but give lower resolution
