Unit 2 - Cell structure and function

Peroxisomes

are organelles that detoxify various substances, producing hydrogen peroxide (H2O2) as a byproduct.

Prokaryotes

do not have any membrane- bound organelles.

Lysosomes

are made when vesicles containing specific enzymes from the trans Golgi fuse with vesicles made during endocytosis. This is a membranous sac of hydrolytic enzymes that can digest macromolecules

Glucose

and ions such as Na+ and K+ are also transported across the plasma membrane via membrane proteins.

ATP

Transport proteins form pumps that use to actively transport solutes across the membrane.

fluid filled sacs

They are that store water, food, wastes, salts, or pigments.

genetic material

The in a prokaryote is one continuous, circular DNA molecule that is found free in the cell in the nucleoid.

Secondary

active transport occurs when something is actively transported using the energy captured from the movement of another substance flowing down its concentration gradient.

Cytoplasm

within a plant cell is usually taken up by a large vacuole which is the central vacuole.

Microtubules

are made up of the protein tubulin, participate in cellular division and movement.

Aquaporins

are water- specific channels.

Carbohydrate side chains

are found only on the outer surface of the plasma membrane.

Tonicity

is used to describe osmotic gradients.

Receptor

- mediated endocytosis: involves cell surface that work in tandem with endocytic pits that are lined with a protein called clathrin.

Microfilaments

are important for movement.

Light microscopes

are used to study stained or living cells.

nucleus

The is usually the largest organelle in the cell. where RNA is synthisised

plant cells

Vacuoles serve multiple functions in .

plasma membrane

In exocytosis, a cell ejects waste products or specific secretion products, such as hormones, by the fusion of a vesicle with the , which then expels the contents into the extracellular space.

Adhesion

proteins form junctions between adjacent cells.

natural flow

Movement against the is called active transport.

Bacteria

and archaea are examples of prokaryotes.

large ingested particles

They have sacs that carry digestive enzymes, which they use to break down old, worn- out organelles, debris, or .

Cilia

and flagella have locomotive properties in single- celled organisms.

Bulk flow

is the one- way movement of fluids brought about by pressure.

Pinocytosis

: the cell ingests liquids.

Ribosomes

can be either free floating in the cell or attached to another structure called the endoplasmic reticulum (ER)

Exocytosis

is basically reverse endocytosis.

hypertonic solution

A(n) has more total dissolved solutes than the cell, while a hypotonic solution has less.

Kidney dialysis

is a specialized process by which the blood is filtered by using machines and concentration gradients.

solute concentration

If an environment is isotonic to the cell, the is the same inside and outside.

Phagocytosis

: the cell takes in solids.

Chloroplasts

contain chlorophyll, which gives plants their characteristic green color. Where photosynthesis is.

ER

The is a continuous channel that extends into many regions of the cytoplasm and provides mechanical support and transportation.

Dialysis

is the diffusion of solutes across a selectively permeable membrane.

Channel

proteins form channels that selectively allow the passage of certain ions or molecules.

ligand

When a particle, or , binds to one of these receptors, the is brought into the cell by the invagination, or "folding in "of the cell membrane.

lipid bilayer

The has hydrophilic outside and hydrophobic on the inside so only hydrophobic things can pass that central zone.

Electron microscopes

are used to study detailed structures of a cell that can not be easily seen or observed by light microscopy.

Receptor proteins

such as hormones, serve as docking sites for arrivals at the cell.

surface area

The and volumes of cells can be calculated using typical geometry formulas.

shape of a cell

The is determined by a network of protein fibers called the cytoskeleton.

surface markers

Cell such as glycoproteins, and some lipids, such as glycolipids, are exposed on the extracellular surface and play a role in cell recognition and adhesion.

plasma membrane

The is important because it regulates the movement of substances into and out of the cell.

Prokaryotes

also have small ribosomes.

Ribosomes

are round structures composed of two subunits, the large subunit and the small subunit. Sites of protein synthesis.

There are two distinct types of cells

prokaryotic cells and eukaryotic cells

This arrangement of phospholipids and proteins is known as the fluid

mosaic model

Pinocytosis

the cell ingests liquids

Phagocytosis

the cell takes in solids

Receptor-mediated endocytosis

involves cell surface receptors that work in tandem with endocytic pits that are lined with a protein called clathrin

2 organelles that contain their own DNA separate from the chromosome

Mitochondria and chloroplast

What domains fall under prokaryotic cells?

Bacteria and archaea

What are the basic features of all cells?

Membrane, cytoplasm, chromosomes, ribosomes

This organelle synthesizes lipids, metabolizes carbohydrates, detoxifies poison, and stores calcium

Smooth ER

This cell is characterized by having DNA in a nucleus that is bound by a nuclear envelope and membrane bound organelles

Eukaryotic cell

The __________ is a selective barrier that allows oxygen, nutrients, and wastes to service the volume of every cell

Plasma membrane

Ribosomes use the information from the DNA to make what

Proteins

This cell type is characterized by having no nucleus, but instead a nucleoid, and no membrane bound organelles

Prokaryotic cell

Diffusion through protein channels is known as what?

Facilitated diffusion

What happens to a plant cell when placed in pure water (hypotonic solution)?

It becomes turgid, cell wall protects from bursting

Site of photosynthesis

chloroplast

These vacuoles pump excess water out of the cell

Contractile

This ER lacks ribosomes

Smooth ER

This organelle modifies products of the ER, manufactures certain macromolecules, sorts and packages materials into transport vesicles

Golgi apparatus

What kind of amino acids will anchor proteins into the membrane?

Non-polar

What is it called when cells are moving molecules against its concentration gradient, from an area of low concentration to an area of high concentration? What does it require to do this?

Active transport, requires ATP

Site of cellular respiration

Mitochondria

These types of vacuoles are formed by phagocytosis

Food

The logistics of carrying out cellular metabolism sets a limit on the size of cells. The ________ to _______ ratio of a cell is critical.

Surface area to volume

Both animals and plants have _________ that allow molecules to pass readily between adjacent cells without crossing plasma membranes.

Cell junctions

These vacuoles are found in many mature plant cells and they hold organic compounds and water

Central

What are the 3 main types of membrane receptors?

G-protein linked, tyrosine kinases, ion channel

Oxidative organelles

Peroxisomes

What happens when you put a red blood cell in pure water (hypotonic solution)? Why?

The cell will burst because water rushes into the cell.

The ________ is continuous with the nuclear membrane

ER membrane

Which part of the phospholipid bilayer is considered hydrophobic?

Fatty acid tail

Which part of the phospholipid bilayer is considered hydrophilic?

Phosphate head

How does the membrane become semipermeable to polar molecules?

Protein channels

_______ is a water channel in bacteria.

Aquaporin

This is the movement of molecules from a HIGH concentration to a LOW concentration. What type of transport is this?

Diffusion, passive transport

What is osmosis?

Diffusion of water across a semi permeable membrane

What does hypertonic mean?

More solute, less water

What does hypotonic mean?

Less solute, more water

What does isotonic mean?

Equal solute, equal water

What happens when you water plants with salt water? Why?

It will wilt because water will leave the plant and go toward the hypertonic solution (salt water).

Signal transduction pathways serve to convert signals on a cell's surface into cellular ________.

Responses

A _______ is a chemical released by a cell in one part of the body, that sends out messages that affect cells in other parts of the organism.

Hormone

What are plant hormones called?

Phytohormones

How are hormones transported?

In the blood

What are the 3 stages of cell signaling?

Reception, transduction, response

Reception occurs when a ________ molecule binds to a ______ protein, causing it to change _____.

Signal, receptor, shape

Membrane receptors that attache phosphates to specific amino acids in proteins are called

Receptor tyrosine-kinases

The activation of this pathway occurs when a GTP displaces the GDP.

G-protein linked receptor pathway

Part of the receptr on the cytoplasmic side serves as an enzyme which catalyses the transfer of phosphate groups from ATP to a certain amino acid on a substrate protein. This is an example of what signal transduction pathway?

Tyrosine kinase receptor pathway

This pathway requires formation of a dimer.

Tyrosine-kinase pathway

The signal molecule that binds to a receptor is typically called a what?

Ligand

What needs to happen to a receptor to initiate the transduction of a signal?

Conformational change (change in shape)

What is the formula for solute potential?

Ys=-iCRT

What is the ionization constant for sucrose? What about NaCl?

Sucrose = 1

NaCl = 2