Honors Biology 9: Unit 1 - Cell Structure and Functions

What does the surface area to volume ratio have to do with cells?

if a cell's surface area to volume ratio is too close, then the cell has to split or else it will combust

What does the endosymbiotic theory state?

some of the organelles in today's eukaryotic cells were once prokaryotic microbes

What is some evidence that supports the endosymbiotic theory?

mitochondria and chloroplasts have circular DNA, 70 s ribosomes, and a double membrane

What is cancer?

an abnormal growth of the cell; there are no "checkpoints"

What are the two main types of cancer?

benign and malignant

Describe benign cancer.

non-invasive, usually not deadly, cured by the removal of the tumor

Describe malignant cancer.

invasive; grows between cells and destroys the tissue; normally treated with radiation, chemotherapy, or surgery

What are the three parts of the cell theory?

all living things are composed of cells, cells are the basic unit of life, and new cells are made from pre-existing cells

What are the three main components of the cell membrane?

phospholipids, proteins, and cholesterol

What is diffusion?

the movement of molecules from high to low concentration areas until equalibrium is reached

How do water, carbon dioxide, and sodium move in and out of the cell?

diffusion

What is the specfic type of diffusion that water uses as a transport method?

osmosis

What is the extracellular matrix?

the outer protective skeleton of the cell plasma membrane in animal cells (the extra wall around the wall)

What is the cytoskeleton?

a network of fibers and fillaments extending throughout the cytoplasm

What does the cytoskeleton do?

it provides support, structure, mobility, and organization throughtout the cell

What are the three parts of the signal transduction pathway?

reception, transduction, and response

Explain the phone analogy of the signal transduction pathway

reception- the phone is ringing, you know nothing about the caller
transduction- answering the phone
response- hanging up the phone and doing what you were told to do

What is a G protein receptor?

proteins that are used to convert signals from outside the cell into responses inside the cell

What are the main types of cellular transport?

Diffusion, facillitated diffusion, and osmosis

What is facillitated diffusion?

the movement of molecules that requires help from a transport protein; doesn't require energy

What are the stages of the cell cycle?

interphase, mitosis, cytokinesis

What are the phases of mitosis?

prophase, metaphase, anaphase, telophase

What happens during interphase?

the cell grows, copies its DNA, and prepares for cell division

What happens during mitosis?

the nucleus of the cell divides

What happens during cytokinesis?

the cytoplasm divides and daughter cells form

Where do proteins go to be packaged?

golgi apparatus

Where do proteins go to be shipped out of the cell?

endoplasmic reticulum (ER)