Honors Biology - Unit 7: Cell Diversity and Processes

The Excretory System: https://knowt.com/flashcards/9ac2d806-b12b-4e24-b813-d654fcb2788d

active transport

involves the movement of a molecule or ion AGAINST its concentration gradient. Lower to higher concentration; requires ATP.

cell membrane

surrounds all cells. Regulates what materials enter and leave the cell; selectively permeable. Composed of phospholipids and proteins.

cell wall

found in plant cells. Surrounds the plasma membrane. Made of cellulose.

centrioles

Found in animal cells. Set of microtubules that move chromosomes during mitosis.

chloroplast

Found in plant cells. Site of photosynthesis. Contain their own DNA, RNA, and ribosomes.

chromatin

consists of DNA and protein. Visible as individual chromosomes in a dividing cell. Found inside the nucleus.

chromosome

a thread-like structure located inside the nucleus of a cell, composed of DNA and proteins, which carries genetic information in the form of genes. 23 pairs; 46 in total.

chromoplast

organelles in plant cells that store and produce pigments, giving plants and their parts colors.

cytoplasm

area between the nucleus and the plasma membrane; contains all cell organelles.

cytosol

fluid in-between the organelles.

cytolysis

the bursting of cells, particularly in animal cells.

cytoskeleton

filaments which help cells maintain their structure and internal organization

concentration gradient

the difference in the concentration of molecules across a space

organism

group of systems working together.

diffusion

the passive movement of molecules from an area of higher concentration to an area of lower concentration until equilibrium is reached.

endocytosis

process which cells ingest (take in) external fluid or large particles

rough endoplasmic reticulum

has ribosomes; makes proteins and transports them to other parts of a cell via vesicles (little packages).

smooth endoplasmic reticulum

lacks ribosomes; involved in various processes such as the creation of lipids, metabolism of carbohydrates, and detoxification of drugs and poisons.

golgi apparatus

modifies and stores products of the endoplasmic reticulum and then sends them to other destinations.

eukaryote

more complex than a prokaryotic cell. Have a nucleus, contain organelles, and found in protists, fungi, plants, and animals.

exocytosis / cell excretion

reverse of endocytosis; vesicles in cytoplasm fuse with the cell membrane. Their contents are released into the cell’s external environment.

glucose

a monosaccharide of carbohydrates

hypertonic

hyper = “more than.” Higher concentration of solute, lower concentration of water outside than inside the cell; water moves out of cell.

hypotonic

hypo = “less than.” Lower concentration of solute and higher concentration of water outside than inside the cell; water moves into the cell.

isotonic

iso = “same.” Solute concentration is the same inside and outside of the cell; equilibrium. No net movement of water.

mitochondrion

“powerhouse” of the cell. Site of cellular respiration and most ATP production. Have their own DNA, RNA, and ribosomes; capable of reproduction. Contain 2 membranes; folded inner membrane (cristae) and smooth outer membrane.

nucleus

stores genetic information and controls cell activities; contains chromatin, nucleolus, and nuclear envelope with nuclear pores.

nucleolus

darkened region inside the nucleus. Makes ribosomal RNA, which will leave nucleus to form ribosomes.

nuclear pores

openings in the nuclear envelope that allow RNA to get out of the nucleus.

microtubules

widest in diameter. Hollow tubes of protein that maintain cell shape and can serve as “tracks” along which organelles are moved. Also form centrioles in animal cells for cell division.

microfilaments

narrowest in diameter. Function in movement and support of cell. Used for muscle contraction.

osmosis

diffusion of water across a selectively permeable membrane due to concentration differences.

passive transport

the movement of molecules from higher to lower concentrations which does not require ATP.

plasmolysis

the loss of turgor pressure in plant cells, causing them to shrink which will cause the plant to wilt or feel soft and bendable.

organelle

membrane-bound structures that perform specific cellular tasks.

phospholipid

two fatty acids joined by a molecule of glycerol; non-polar tail and polar head

prokaryote

lack a true nucleus and membrane-bound organelles. DNA is concentrated in nucleoid. Have thick cell wall made of glycoproteins. Some have flagella or pili. Includes archaea and eubacteria.

ribosome

site of protein synthesis; can be free floating in cytoplasm or attached to the rough endoplasmic reticulum.

plastid

organelles surrounded by two membranes and contain DNA. Some store starches or fats, while others contain pigments to absorb light

turgor pressure

the pressure water molecules exert against the cell wall

vacuole

small container that store substances in cells. Food is stored in small food vacuoles, fusing with lysosomes which digests the food. Animals may have multiple small food vacuoles/none while plant cells have a single, large vacuole (central vacuole).

vesicle

a small package that transports proteins to other parts of the cell from the rough endoplasmic reticulum.

facilitated diffusion

a type of passive transport which substances move from high to low concentration via certain integral proteins; no ATP.

synthesis

the production of chemical compounds by reaction from simpler materials.

marker protein

the “name tag” of cells. Elongated proteins that have carbohydrates on the surface that signal that the cell is a part of the organism.

channel protein

proteins that are donut-shape which act as passageways; only certain molecules and ions can pass through these proteins.

receptor protein

boulder-shaped proteins that latches on a particular type of molecule in order to convey information from the outside of the cell to the inside of the cell.

insulin

a protein which lowers blood sugar level by stimulating body cells to absorb glucose

lysosome

Found in animal cells. Produced by endoplasmic reticulum and golgi apparatus. Contains digestive enzymes.

integral protein

proteins embedded in the bilayer. Some have carbohydrates to hold other cells together, or sites for viruses or chemical messengers can attach. Some have channels or pores in which certain molecules can move through.

peripheral proteins

located on the surface of the interior and exterior of the cell membrane. Weak bonds link peripheral proteins to the membrane or to other proteins in the lipid bilayer.

cholesterol

human steroid which is needed for nerve cells and other cells to function normally