Exam 1 Flashcards
What are Prokaryotic cells
Small, singled with simple structure
What are Eukaryotic cells
Larger, and more complex cells (all multicellular and some unicellular)
Nucleus function
Contains DNA, and controls replication of DNA
Mitochondria function
The cells energy transformers (creating ATP)
Smooth endoplasmic reticulum
without ribosomes, synthesizes lipids
Rough endoplasmic reticulum
transports proteins to various sites within a cell
Golgi apparatus (Golgi body)
Package and export of substances out of the cell
Lysosome
they break down non-functioning cell organelles and substances
Cytoskeleton
Supports and strengthens the cell
chloroplasts
Convert energy from the sun using photosynthesis
Cell wall
Provides protection shape and support of the cell
Ribosomes
manufacture proteins (makes)
Vacuole
Storage of nutrients, waste disposal
Plasma membrane (cell membrane)
the outmost barrier of the cell, separating it from other cells
What organelles are different from animal and plant
plants have cell wall chloroplasts and large centralised vacuole, lysosomes are in animal cells
What are the main elements of the plasma membrane
Phospholipids (containing hydrophilic heads, and hydrophobic tails)Channel proteins, and carrier proteins
What is the fluid mosaic model
The model that represents the plasma membrane (phospholipid bilayer and proteins)
What are channel proteins
proteins that channel molecules in by creating a hydrophilic passage across the membrane
What are carrier proteins
Proteins that carry molecules by changing shape and carrying across the membrane, these carry hydrophilic uncharged substances
How do gases cross the plasma membrane
through simple diffusion
How do hydrophobic molecules cross the plasma membrane
simple diffusion
How do small polar molecules cross the plasma membrane
simple diffusion
How do large polar molecules cross the plasma membrane
Facilitated diffusion or active transport
what is a solute
substance that is dissolved
what it a solvent
liquid which a solute dissolves
what is simple diffusion
the movement of solutes across the phospholipid bilayer from a region of higher concentration to a region of lower concentration
what is facilitated diffusion
diffusion using a protein such as channel or carrier protein
What is osmosis
Diffusion of water molecules from an area of high free water to an area of low free water
what is a isotonic solution
a solution with equal solute and solvent concentration
what is a hypotonic solution
having a lower solute concentration than the cell contents (the cell will expand)
What is a hypertonic solution
Having a higher solute concentration than the cells content (the cell shrinks)
What is active transport
the process of moving substances from an area of low concentration to an area of high concentration (uses energy)
what is bulk transport made up of
Endocytosis and exocytosis (both require energy)
What is pinocytosis
bulk movement of material that is in a solution (liquid) into cells
What is phagocytosis
bulk movement of solid material into cells
how does endocytosis work
plasma membrane folds around a substance to transport it across the plasma membrane into the cell
how does exocytosis work
unwanted substances fuse with the plasma membrane and it wraps around it and then expels it out of the
Which transport mechanism requires energy
active transport and bulk transport
what is binary fission
a form of asexual reproduction, that creates 2 new cells that are almost identical
what are the steps in the cell cycle
Interphase, Mitosis, cytokinesis
what is interphase
where the cell grows and replicates its DNA
what are the parts of Interphase
G1 stage, S stage and G2 stage
What happens in the G1 stage
the cell undergoes growth, increasing the amount of cell cytosol (liquid inside cell)
What happens in the S stage
parent cell synthesizes or replicates its DNA
What happens in the G2 stage
further growth of the cell in preparation for mitosis
What are the stages in mitosis
Prophase, Metaphase, anaphase and telophase
What happens in Prophase
chromosomes condense and become visible, spindle forms
What happens in Metaphase
the pair of chromosomes, line up in the middle of the cell
What happens in Anaphase
The sister chromatids separate and are pulled to opposite ends of the cell
what are chromatids
one of two identical threads in a replicated DNA molecule
What happens in telophase
Nuclear membrane forms around each separate group of chromosomes.
What happens in cytokinesis
division of the cytoplasm, there are now 2 new daughter cells
What are cell checkpoints
the are checkpoints that ensure that a complete and damage free copy is being created
what are the 3 checkpoints
G1 checkpoint, G2 checkpoint, M checkpoint
what happens in the G1 checkpoint
Checked to see if it is large enough, has enough nutrients and signals from other cells have been gotten
What happens in the G2 checkpoint
checked to see if its large enough and chromosomes have been successfully duplicated
What happens in the M checkpoint
checked if all chromosomes are attached to the mitotic spindle
What happens if the checkpoint isn’t met
apoptosis will occur
What is apoptosis
programmed cell death, a natural and necessary mechanism to trigger the death of the cell
what happens in apoptosis
the cell shrinks and forms blebs, the nucleus then collapses then the cell breaks into apoptotic bodies and removed via phagocytosis
If apoptosis doesn’t occur or at a slow rate what can form
cancer or other illness such as tumors
What is cell differentiation
the process of cells, tissues and organs getting specialized features
what is specialization
the adaptation of something for a specific function
What are stem cells
stem cells are undifferentiated cells
what is a totipotent stem cell
cells that have the potential to give rise to all cell types
what is a pluripotent stem cell
cell of the primary germ layer, that can differentiate into many cell types but not all
What are the parts of the germ layer
ectoderm, mesoderm and endoderm
what’s the ectoderm
the most external primary germ layer
what’s the mesoderm
the middle primary layer of the germ layer
what’s the endoderm
the innermost primary germ layer
what is a multipotent stem cell
cells that have the ability to differentiate into closely relative family of cells
what is a unipotent stem cell
have the ability to produce only cells of their own type
What are embryonic stem cells
undifferentiated stem cells obtained from early embryonic tissue, that can turn into many cell types
What are adult stem cells (somatic stem cells)
undifferentiated cells obtained from various sources and capable of turning into related cell types
What are induced pluripotent stem cells
a stem cell that has been genetically reprogrammed to return to an undifferentiated embryonic state
What are the 7 levels of the hierarchy of plants
chemical, organelle, cellular, tissue, organ, organ system and organism
What are the 2 systems in a plant
Root (below ground) and shoot (above the ground) systems
what vascular tissues make up a plants transport system
xylem and phloem
what’s the xylem
hollow and dead cells that transports water and minerals
What’s the phloem
living cells, that transport sugars
what is transpiration
loss of water from the surfaces of a plant
How is the water lost in transpirtation
Through the stomata, they will open causing the transpiration rate to increase or close and transpiration rate decreases
What is homeostasis
relatively constant physiological state of the body despite changes in the external environment
what are the components of a stimulus response model
stimulus, receptor, control center, effector and response
what happens in the stimulus stage
a change, either increase or decrease, in the level of an internal variable (body temp)
What happens in the receptor stage
the structure that detects the change sends signals to the control center
what happens in the control center stage
the central nervous system evaluates the stimulus and sends to effector for any corrections
what happens in the effector stage
the structure adjusts the control center signal to make it correct
what is negative feedback
a control system that maintains the body internal environment at a relatively steady state
what is positive feedback
A mechanisms increase a response in order to achieve a particular result.
the endocrine system
the endocrine system is made up of ductless glands, which secrete hormones into the blood. These participate in feedback loops and regulate internal functions
endocrine glands
scattered widely throughout the body and their positioning does not necessarily reflect the location
hormones
A chemical messengers that are produced at one endocrine site and carried in the blood to influence target cells that may be quite distant
hypothalamus
registers change in the core body temperature and also receives information about temperature changes from the thermorecpetors skin
thermoreceptors
simple sensory receptors that are located in the skin and respond to changes in temperature
the thyroid and thermoregulation
hormones regulate many aspects of metabolism. Over and under-protection of hormones can effect metabolic aspects for thermoreuglation
