BIOCHEM LAB MIDTERMS

pH

pH

______is a measure of how acidic or basic a chemical is when it's in an aqueous (water) solution.

7

A neutral pH value is____

bases

Substances with a pH greater than 7 up to 14 are considered______

acids

Chemicals with a pH lower than 7 down to 0 are considered_____

acidic

Most fruits, vegetables, and body fluids are_____

true

Not All Liquids Have a pH Value

true or false?

true

If there's no water, there's no pH

true or false?

no

vegetable oil

does it have pH value? yes or no

true

Fruits and vegetables tend to be acidic?

true or false

neutral

Milk is often considered to be____

true

Milk becomes more acidic over time

true or false?

acidic

Distilled water tends to be slightly_____

neutral

Pure water is nearly_____

acidic

rainwater tends to be slightly_____

alkaline or basic

Natural water rich in minerals tends to be_____

paper test strips

The simplest method to measure pH is to use ______

“power of hydrogen”

pH is an abbreviation for_____

buffering system

the human body; changes to blood pH could have a devastating effect, so there is a mechanism within the body known as the bicarbonate_____ _____

weak acid

A buffer solution is made up of a ______and its conjugate base or a weak base and its conjugate acid

a buffered pH

________is required for most enzymes to function correctly

buffer capacity

The amount of a strong acid or base that a buffer solution can take before significant pH changes occur is known as the__________

carbonate buffer

the body uses three buffer systems: carbonates, phosphates, and proteins

among these 3 which is the most important system?

true

Almost all proteins can function as buffers.

true or false?

Hemoglobin

______is the principal protein inside red blood cells and accounts for one-third of the mass of the cell

Acidosis

It is a condition in which occurs when there is overproduction of acid in the body fluids or the blood pH falls below 7.35

Alkalosis

It is a condition in which occurs when there is excessive blood alkalinity in the body fluids or the blood pH rises above 7.45 and a pH above 7.8 is fatal.

Prokaryotic Cells

these are unicellular organisms that do not develop or differentiate into multicellular forms

true

Prokaryotic Cells lack a nucleus and membranous organelles.

true or false?

Eukaryotic Cells

These cells contain a nucleus and membrane-bound compartments, called organelles, in which specific metabolic activities take place.

Cytosol

It is the fluid portion of the cell.

Endoplasmic Reticulum

Responsible for intracellular transport

true

The mitochondrion is believed to be a eukaryotic cell engulfed by a prokaryotic cell.

true or false?

Lysosome

Suicide bag of the cell

Peroxisome

Detoxifies the cell

Cell membrane

it is also called plasma membrane

Cytoplasm

Jelly-like matrix that surrounds the nucleus and is bounded by the cell membrane

false

The genetic material of a prokaryotic cell is found in its nucleus.

true or false?

true

Smooth ER is agranular?

true or false

no attached ribosomes

agranular means?

with ribosomes

granular means?

Smooth ER

this is the site for the synthesis of cholesterol and phospholipids

Rough ER

Receives proteins that are synthesized by ribosomes.

True

Mitochondrion contains a DNA

true or false?

Golgi Apparatus

Modifies, packages and transports protein and Produces lysosomes

Lysosomes

Surrounded by a single membrane and contains powerful enzymes capable of digesting or breaking down all organic materials.

Nucleus

-A rounded structure at the center of the cell

-Controls the metabolic activities.

-Frequently the largest structure in the cell.

-Contains the DNA

false

Animal Cell has Vacuoles

true or false?

true

Plant cells is larger than animal cells

true or false?

chlorophyll

what is a green pigment that captures light energy to drive the reactions in to photosynthesis?

Active Transport

Types of Transport:

-Requires energy

-Goes AGAINST the concentration gradient

- From Low Concentration to High Concentration or Against a Gradient Concentration. Utilized by Pumps/Carrier Proteins. Also knows as Uphill Transport

Passive Transport

Types of Transport:

-Does not require energy

-Goes with the concentration gradient

- From High Concentration to Low Concentration or Along with a Gradient Concentration. Also known as “Downhill transport”.

Diffusion / Simple Diffusion

_______is the random movement of molecules from an area of high concentration to low concentration

Osmosis

_______is the diffusion of water across a membrane Moves from HIGH water concentration to LOW water concentration

Isotonic

Cells in solution:

A solution whose solute concentration is the same as the solute concentration inside the cell.

Hypotonic

Cells in solution:

A solution whose solute concentration is lower than the solute concentration inside a cell

Hypertonic

Cells in solution:

A solution whose solute concentration is higher than the solute concentration inside a cell.

Facilitated Diffusion

Type of Diffusion:

-Uses transport proteins to move high to low concentration

-Molecules will randomly move through the pores in Channel Proteins.

Channel Proteins

TYPES OF TRANSPORT PROTEINS:

are embedded in the cell membrane & have a pore for materials to cross

Carrier Proteins

TYPES OF TRANSPORT PROTEINS:

can change shape to move material from one side of the membrane to the other

The formation of a purple ring at the  junction of two liquids

Visual evidence of positive result:

Molisch’s Test

brick-red precipitate

Visual evidence of positive result:

Fehling’s Test

grey-black precipitate or a silver mirror

Visual evidence of positive result:

Tollen’s Test

forms a black precipitate

Visual evidence of positive result:

Nylander’s Test

Brick-red ppt

Visual evidence of positive result:

Benedict’s Test

blue-green solution

Visual evidence of positive result:

Bial’s Orcinol Test

cherry-red solution

Visual evidence of positive result:

Seliwanoff’s Test

true

Measure the pH of the buffer solution, Adjust the pH if applicable (pH= 5.22) by adding drops of HNO3 or NaOH

true or false?

false

Surfactants are compounds that increase the interfacial tension between two liquids, between a gas and a liquid, or between a liquid and a solid

true or false?

true

Pure water has a neutral pH close to 7.0 at 25 degrees Celsius

true or false?

true

The human body is composed of billions of cells that provide structure for the body. take in nutrients from food, convert nutrients into energy and carry out specialized functions

true or false?

true

Polysaccharides, the most complex of all carbohydrates. composed of many saccharide units. can be hydrolyzed by enzymes or by heating with dilute acids

true or false?

false

Dextrin a product of partial hydrolysis of starch gives a color red solution and glycogen. a highly branched complex polysaccharide. gives a pale reddish-brown solution

true or false?

true

to lose weight, some individuals adhere to “low-carb” diets

true or false?