The Cell Flashcards
Somatic cell
All cells except sex cells
Sex cells
reproductive cells
Ex: sperm and oocytes
Cell membrane
function:
isolation, protection, sensitivity, support, controls entrance/exits of materials
Cytosol function:
distributes materials by diffusion
cytoskeleton function:
strength and support
movement
Microvilli function:
increase surface area to facilitate absorption of extracellular materials
Cillia function:
movement of materials over cell surface
Ribosomes function:
protein synthesis
Proteasomes
Breakdown and recycling of intracellular proteins
Mitochondria function:
Produces 95% of the ATP required by the cell
Endoplasmic reticulum (ER) function:
-Synthesis of secretory products
-Intracellular storage and transport
Smooth ER function:
Lipid and carbohydrate synthesis
Rough ER function:
Modification and packaging of newly synthesized proteins
-Surface covered in ribosomes
Golgi apparatus function:
Storage, alternation, and packaging of secretory products and lysosomal enzymes
Lysosomes function:
Intracellular removal of damaged organelles of pathogens
Peroxisomes function:
Neutralization of toxic compounds
Nucleus function:
control of metabolism, storage and processing of genetic information, control of protein synthesis
Nucleolus function:
Site of rRNA synthesis and assembly of ribosomal subunits
Phospholipid bilayer of the membrane
Double layer of phospholipid molecules that create barrier
Integral proteins (membrane)
Found within the membrane
Peripheral proteins (membrane)
Found in the inner or outer surface of the membrane
Glycocalyx
Sticky sugar coat outside membrane
Nonmembranous organelles
-no membrane
-direct contact with cytosol
Membranous organelles
-covered with plasma membrane
-isolated from cytosol
Microfilaments
thin filaments composed of the protein Actin
-pairs with thick filaments of myosin for muscle improvement
Intermediate filaments
Mid-size and durable
-strengthen cell and maintain shape
Microtubules
Large, hollow tubes of tubulin that strengthen cell and anchor organelles, change cell shape
Centrioles
form spindle apparatus during cell division
Free ribosome
cell organelles that are unattached to any membrane and float freely in the cytoplasm of a cell. They are responsible for producing proteins that are used within the cell
Fixed ribosomes
ribosomes that are attached to the rough endoplasmic reticulum (ER)
Cisternae
storage chambers within golgi apparatus
Secretory vesicles
modify and package products for exocytosis
Membrane renewal viscles
Add or remove membrane components
Transport vesicles
carry materials to and from Golgi apparatus
Exocytosis
the ejection of secretory products and waste
Cells
the basic structural and functional units of life
Chromosomes
tightly coiled DNA
Chromatin
loosely coiled DNA
Genes
A distinct sequence of DNA bases, forming part of a chromosome
DNA (code)
instructions for every protein in the body
Gene (code)
DNA instructions for 1 protein
3 bases =
1 amino acid
Transcription
Copying instructions from DNA to mRNA
Translation
ribosome reads code from mRNA and assembles amino acids into a polypeptide chain
Genetic information must be:
transferred into the cytoplasm where proteins are synthesized
True or false:
Only ONE side of DNA codes for a protein.
TRUE
mRNA
messenger RNA
transcribed from DNA by complementary base pairing.
Ex: Adenine pairs to uracil
The genetic code
a triplet code compromised of three nucleotide bases in a sequence
Selective permeability
allows some materials to move freely but restricts others based on
-size
-electrical charge
-shape
-lipid solubulity
Diffuse transport
passive with no energy required
Carrier-mediated transfer
passive or active pending the type of carrier
vesicular transport
active and requiring energy through ATP
What are the seven methods of transport?
-diffusion
-osmosis
-facilitated diffusion
-active transport
-secondary active
-endocytosis
-exocytosis
Diffusion
Molecular movement of solutes; direction determined by relative concentrations
Osmosis
Movement of water molecules towards solution containing relatively higher solute concentration
Facilitated diffusion
carrier proteins passively transport solutes across a membrane down a concentration gradient
active transport
carrier proteins actively transport solutes across a membrane, often against a concentration gradient
secondary active transport
carrier proteins passively transport two solutes, with one moving down concentration gradient
Endocytosis
creation of membraneous vesicles containing fluid or solid material
Exocytosis
fusion of vesicles containing fluid or solids (or both) with the call membrane
Concentration
the amount of solute in a solvent
concentration gradient
more solute in one part of a solvent than another
What are 5 factors that affect diffusion rates?
-distance
-temperature
-gradient size
-electrical forces
Materials that can pass through transmembrane proteins
-water soluble
-ions
Osmotic pressure
the force of a concentration gradient of water equals the force needed to block osmosis
Tonicity
ability of a solution to change the volume of cells by altering their water content
Isotonic solution
a solution that does not cause osmotic flow of water in or out of a cell
Hypotonic solution
gain water through osmosis
Hypertonic solution
a solution with higher osmotic pressure
Characteristics of carrier-mediated transport
-1 transport protein = 1 set of substrates
-rate depends on transport proteins
- regulation such as hormones
Cotransport
2 substances move in the same direction at the same time
Countertransport
1 substance moves in while another moves out
Carrier proteins
transport molecules too large to fir through channel
Active transport proteins:
move substrates against concentration gradient and require energy
receptor-mediated endocytosis
cells absorb metabolites, hormones, proteins – and in some cases viruses – by the inward budding of the plasma membrane
Pinocytosis
cells take in fluid and dissolved substances through the cell membrane
Ex: Cellular drinking
Phagocytosis
cell, or phagocyte, surrounds and destroys foreign substances and dead cells
Mitosis
the process by which a cell replicates its chromosomes and then segregates them
Interphase
non-diving state but cell is metabolically active
-chromosomes are long and thin
Prophase
-chromosomes shorten and thicken
-spindles start to form
Metaphase
-chromosomes line up forming a line
Anaphase
-centromeres divide
-chromosome halves migrate to opposite poles of the cell
Telophase
cell starts to form the peanut shape
Cytokinesis
the final stage of cell division where the cytoplasm of a single cell physically divides into two separate daughter cells
True or false
cell division balances cell loss
TRUE
Oncogenes
mutates genes that cause cancer
Tumor
enlarged abnormal mass of cells
Benign tumor
non cancerous tumor
Centromere
structure in a chromosome that holds together the two chromatids
Ex: the DNA’s belt that gives it an X shape
Kinetochore
a protein structure that forms on a chromatid during cell division and allows it to attach to a spindle fiber on a chromosome.
