Cells, Organelles & Transport (DAT booster)

Hierarchy of membrane permeability (from most to least permeable)

• (MOST) Small, hydrophobic molecules: O2, CO2, N2, steroid hormones

• Small, uncharged, polar molecules: H2O, urea, glycerol, NH3

• Large, uncharged, polar molecules: glucose, sucrose

• (LEAST) Ions (charged): H+, Na+, HCO3-, K+, Ca2+, Cl-, Mg2+

Which diffuses most easily through the phospholipid bilayer?

Hydrophobic molecules

Which is least favorable to produce through the phospholipid bilayer?

Ions

Which of the following cannot diffuse through the phospholipid bilayer?

Calcium

The glycocalyx is present outside of some _____.

Animal cell membranes & bacterial cell walls

What are the functions of the glycocalyx?

• cell adhesion

• cell-to-cell recognition

• maintenance of blood vessels

• physical protection of the cell from infection

What is NOT a function of the glycocalyx?

structural support of the cell

______ are common cell surface markers used regularly for cell-cell recognition

Glycoproteins

The animal cell membrane is made up of _____.

Phospholipid membrane, cholesterol, membrane proteins

Cholesterol (animal cell) & sterol (plant cell) aid with ____.

membrane fluidity, stability and permeability

______ is analagous to the role of cholesterol in plant cell membranes?

Sterols

_____ possess centrioles

Animals

Microtubules are made up of _____.

tubulin

Microfilaments are made up of ____.

actin

A transmembrane protein is _____.

embedded from one side to the other side of the cellular membrane

A transmembrane protein is a type of _____.

integral protein

_______ are used to distinguish between self and foreign pathogens.

Glycoproteins

_______ bind to hormones and other trigger molecules.

Receptor proteins

A peripheral protein is attached by _____.

loose attachment to cellular membrane

An integral protein is _____.

embedded in the cellular membrane

When DNA is wrapped into a bundle w/ eight histone proteins it is a _____.

nucleosome

______ is the site of ribosome (RNA) synthesis in an animal cell.

Nucleolus

______ is used to synthesize ribosomes in a eukaryotic cell.

rRNA

____ provides mechanical support to maintain the shape of the nucleus.

Nuclear lamina

____ aids in chromatin organization.

Histones

The movement within the cytoplasm is called _____.

cyclosis

The organelle that assembles glycoproteins is called the ____.

rough endoplasmic reticulum

The organelle that produces lipids & steroid hormones is called the ____.

smooth endoplasmic reticulum

_____ are stored in the sarcoplasmic reticulum,

Calcium ions

The flattened sacs in the Golgi apparatus are called _____.

cisternae

______ is used by peroxisomes to oxidize substances,

Hydrogen peroxide

One of the most common proteins found in intermediate filaments is ____.

keratin

_______ form the spindle apparatus during cellular division.

Microtubules

The digestive enzymes inside lysosomes function at a ____.

low pH

Intermediate filaments _____.

provide support to maintain cellular structure

Microtubule Organization Centers are found everywhere besides _____.

bacterial cells

What is the function of contractile vacuoles?

Pumps and collects water using active transport in some protist organisms

Microtubule Organizing Centers are found as ____.

9×3 array

What is the function of plastids?

site of photosynthesis in plant cells

What is the function of the mitochondria?

Fatty acid catabolism

_____ is a highly condensed chromatin in a eukaryotic cell.

Chromosome

_____ is NOT a membrane bound organelle.

Ribosome

• nucleus

• lysosome

• endoplasmic reticulum

• mitochondria

are membrane-bound organelles

A lack of water can cause a plant to appear wilted due to a _____.

reduction in turgor pressure

A human disease results in an inability to synthesize enough steroid hormones. Which organelle is likely affected by the disease?

smooth endoplasmic reticulum

What is the function of the smooth ER?

• lipid synthesis (synthesizing steroid hormones)

_____ is the most common protein found in the extracellular matrix.

Collagen

Cells can bind to the extracellular matrix with ____.

hemidesmosomes

What best describes cyclosis (cytoplasmic streaming)?

The circular movement of the cytoplasm around cell transport molecules.

Animal cells that experience mechanical stress like the skin tend to have ___.

desmosomes

_____ produces a seal to prevent the movement of molecules b/w cells.

Tight junctions