Unit 2 Flashcards
The Smallest until that shows the properties of life, which means it has a capacity for metabolism, homeostasis, growth, and reproduction
cell
Type of cell that starts life with a nucleus
eukaryotic cell
Smaller and simpler, has no nucleus
prokaryotic cell
The cells outer membrane
plasma membrane
Double-membraned sac holds a eukaryotic cells DNA
nucleus
In prokaryotic cell, region of cytoplasm where DNA is concentrated
nucleoid
a semifluid mixture of water, sugars, ions, and proteins between the plasma membrane and the region of DNA
cytoplasm
Structures on which proteins are built, are suspended in cytoplasm
ribosomes
Physical relationship, strongly influences cell size and shape
surface-to-volume ratio
A double layer of lipids organized so that their hydrophobic tails are sandwiched between their hydrophilic heads
lipid bilayer
Surrounds the plasma membrane of nearly all prokaryotes
Cell wall
Slender cellular structures used for motion
Flagella/cilia
Project from the surface for some bacteria species, helps cling or move across surfaces
pili
Single-celled organisms live in a shared mass of slime
biofilm
A structure that carries out a specialized function inside a cell
organelle
Consists of two lipid bilayers folded together as a single membrane
Nuclear envelope
A viscous fluid similar to cytoplasm
nucleoplasm
irregularly shaped region where subunits of ribosomes are assembled from proteins and RNA
nucleolus
The names for all DNA, together with its associated proteins, in the nucleus
chromatin
Each molecule of DNA, together with its many attached proteins
chromosome
an extension of the nuclear envelope, lipid and protein synthesis
ER, Smooth and Rough ER
Contains enzymes that digest fatty acids and amino acids
peroxisomes
isolate and dispose of waste, debris, or toxic materials
Vacuole
puts finishing touches on proteins and lipids, sorts and packages them into vesicles to carry them to the cell membrane
golgi body
Vesicles that contain powerful digestive enzymes
Lysosomes
Specializes in making ATP
mitochondria
Membrane-enclosed organelles that function in photosynthesis or storage in plants and algal cells
Plastid
Organelles that are specialized for photosynthesis
choloroplast
Keeps plant cell and structures firm
central vacuole
Complex mixture of fibrous proteins an polysaccharides so secreted by cells,and varies with the type of tissue
extra cellular matrix
Structures that connect a cell to other cells and to the environment
Cell junction
An interconnected system of many protein filaments between the nucleus and plasma membrane
cytoskleton
Are long, hollow cylinders that consisted of subunits of the protein tubulin
microtubules
Are fibers that consists primarily of subunits of the globular proteins actin
microfilaments
A barrel shaped structure that plays a role in microtubule formation in cilia, flagella, and eukaryotic spindles
centriole
Functions as “false feet”
pseudopod
A cell membrane has a mixed composition(mosaic) of lipids and proteins, the interactions and motions of which impart fluidity to it
fluid mosaic model
Protein or RNA that catalyzes(speeds) a reaction without being changed by it
Enzymes
proteins that fasten cells to other cells and to ECM in animals tissues
adhesion proteins
Proteins that function as unique identity tags for each individual or species
Recognition proteins
Proteins that bind to a particular substance outside the cell, such as a hormone
receptor proteins
Are integral membrane proteins that move specific ions or molecules across a lipid bilayer
transport proteins
The membrane allows some substance but not others to cross it
selective permeability
Is the number of molecules or ions of a substance per unit volume of fluid
concentration
A difference in concentration between two adjacent regions
concentration gradient
Is the net or overall movement of molecules or ions down a concentration gradient
diffusion
A concentration gradient drives that diffusion of a solute across a cell membrane
passive transport
Movement of substances against the concentration gradient using energy (ATP).
active transport
Are active transporters that move calcium ions across muscle cell membranes
calcium pump
Move two substances at the same time
Cotransporter
A vesicle that moves to the cell surface to leave the cell
exocytosis
A cell that engulfs a substance to be inside the cell
endocytosis
Is an endocytic pathway - cell eating
phagocytosis
Water molecules tend to diffuse in response to their own concentration gradient
osmosis
A fluid with a low solute concentration relative to another fluid
hypotonic
A fluid with a higher solute concentration
hypertonic
Two fluids withs the same solute concentration
isotonic
Pressure that a volume of fluid exerts against a cell wall, membrane, tube, or anybody structure that holds
hydrostatic pressure
The amount of hydrostatic pressure that can stop water from diffusing into cytoplasmic fluid or other hypertonic solution
osmotic pressure
a nuclear division mechanism that occurs in the somatic cells(body cells) of multicellular eukaryotes (asexual reproduction) 2 identical cells
mitosis
a nuclear division mechanism that precedes the formation of gametes or spores, and it is the basis of sexual reproduction (4 non-identical cells)
meiosis
Two molecules of DNA stay attached as a single chromosome until late in the nuclear division
sister chromatid
A double stranded DNA molecule winds twice around “spools” of proteins
histone
The smallest unit of structural organization in eukaryotic chromosomes
nucleosome
The region where sister chromatids constrict where they attach to one another
centromere
The life of a cell passes through a sequence of events between each cell division
Cell cycle
A cell copies all of its DNA before it divides
DNA replication
Consists of G1, S, and G2 phases, and includes the replication of DNA
interphase
Is the sum of all chromosomes in a cell of a given type
chromosome number
Describes a cell that has two copies of each chromosome
Diploid
A dynamic network of microtubules that is responsible in the separation of sister chromatids during mitosis
biopolar spindle
Chromosomes condense and become visible
Prophase
The alignment of the chromosomes at the midline
Metaphase
The interval when sister chromatids of each chromosome separate and move toward opposite spindle poles
Anaphase
The two clusters of chromosomes reach the spindle poles, creating a cleavage furrow.
Telophase
Cytoplasmic division -divides cell organelles throughout the cytoplasm
cytokinesis
Is anchored to the plasma membrane
contractile ring
Vesicles and their wall building contents fuse into disk shaped structures
Cell plate
Active genes that stimulate cells to grow and divide
Growth factors
An abnormal mass in the surrounding tissues
Tumor
Abnormal masses of cells that lost control over how they grow and divide
Neoplasms
When the abnormally dividing cells of a malignant neoplasm disrupt body tissues, physically and metabolically
Cancer
Regions in DNA that encodes information about traits
Genes
One parent produces offspring, so all of its offspring inherit the same number and kinds of genes
Asexual reproduction
Genetically identical copies of the parent
Clone
The process involving meiosis, formation of mature reproductive cells, and fertilization
Sexual reproduction
Different forms of a gene
Allele
Chromosomes have the same length, shape, and collection of genes
Homologous
Immature reproduced cells
Germ cells
Mature reproductive cells
Gametes
Single set of chromosomes
Haploid
The first cell of a new individual
Zygote
The process by which a chromosome and its homologous partner exchange corresponding segments
Crossing over
Are diploid spores form by meiosis in their specialized parts
sporophytes
A multi celled haploid body inside which one or more gametes form
gametophytes
Spermatid mature as a male gamete
Sperm
Matured female gamete, also known as ovum
Egg
The fusion of two gametes produces a zygote
Fertilization
Discovered cells by observing cork under a microscope.
Robert Hooke
Improved microscopes and observed the first living cells (bacteria, protozoa).
Anton van Leeuwenhoek
Cell Theory
• All living things are made of cells.
• Cells are the basic unit of structure and function.
• All cells come from pre-existing cells.
Phospholipid bilayer with proteins, cholesterol, and carbohydrates.
Cell Membrane Composition
use light, lower magnification, view live specimens.
Light microscopes
use electron beams, higher magnification, view non-living specimens.
Electron microscopes
Composed of hydrophilic heads and hydrophobic tails, forming a barrier.
Phospholipid Bilayer
Parts of a Phospholipid
Head (phosphate group, hydrophilic), Tail (fatty acid chains, hydrophobic).
Movement of molecules from high to low concentration without energy.
Simple Diffusion
Passive transport through proteins for large or polar molecules.
Facilitated Diffusion
Movement of water across a membrane from low to high solute concentration.
Osmosis
Bulk Flow
Movement of fluids with suspended substances in bulk, such as blood flow.
Pure water with no dissolved solutes.
Distilled Water
TEM(Transmission Electron Microscope)
Used for internal structures
SEM(Scanning Electron Microscope)
Used for surface details
Phagocytosis
Process where a cell engulfs large particles or other cells.
cell bursts in hypotonic solution
Lysis
cell shrinks in hypertonic solution
Crenation
pressure of the cell membrane against the cell wall in plant cells.
Turgor Pressure
First immortal human cell line; crucial for research on cancer, vaccines, and more.
HeLa Cells
DNA Structure
DNA is a double helix made of nucleotides that codes for proteins.
Process that produces haploid gametes with genetic diversity.
Meiosis
Identical copies of a chromosome connected by a centromere.
Sister Chromatids
DNA in a Duplicated Chromosome
Two copies (sister chromatids).
Cell Cycle
G1: growth, S: DNA replication, G2: preparation for mitosis, (PMAT)
Cell Division in Life
Cells divide during growth and healing; stop in adulthood, except for skin, gut, and blood cells.
Cell with two sets of chromosomes, one from each parent.
Diploid
Prophase
Chromosomes pair up
Metaphase
Chromosomes line up at equator
Anaphase
Sister chromatids pulled apart
Telophase
cell pinches in the middle (cleavage furrow)
Cytokinesis
Division of the cytoplasm, forming two daughter cells.
Uncontrolled cell growth forming a mass.
Tumor
Non-cancerous tumor that doesn’t spread.
Benign
Cancerous tumor that spreads and can be deadly
malignant
Reduces chromosome number by half, creating genetic diversity.
Meiosis
Produces genetically identical offspring (low variability).
Asexual Reproduction and Low-Genetic Variability (Mitosis)
Reproductive Parts of a Flower
Stamens (male), pistils (female).
Human Reproductive Cells
Sperm (male) and egg (female).
Variant form of a gene.
Allele
Identical halves of a duplicated chromosome.
Sister Chromatid
One half of a duplicated chromosome.
Chromatid
Exchange of genetic material between homologous chromosomes.
Crossing-over
Chromosomes with the same genes, one from each parent.
Homologous
Occurs in prophase I of meiosis.
Crossing-over
Small cell produced in meiosis in females; usually non-functional.
Polar Body
Fate of Polar Bodies
They usually degenerate
Immature sperm cell formed in meiosis.
Spermatid
