Biology Lecture Review: Cell Transport, Genetics, and Biotechnology

A comprehensive set of question and answer flashcards covering cell transport mechanisms, organelles, cell cycle regulation, genetics, DNA replication, and biotechnology based on lecture transcripts.

What is the definition of passive transport?

The movement of molecules across a cell membrane that does not require energy input by the cell.

How is diffusion defined in cell biology?

A type of passive transport involving the movement of molecules in a fluid or gas from an area of higher concentration to lower concentration.

What is a concentration gradient?

The difference in concentration of a substance from one area to another.

What term describes the diffusion of water?

Osmosis.

What occurs to a cell placed in a hypertonic solution?

The solution has a higher concentration of dissolved particles than the cell, causing the cell to shrivel or die.

What occurs to a cell placed in a hypotonic solution?

The solution has a lower concentration of dissolved particles than the cell, causing the cell to expand or burst.

How does active transport differ from passive transport?

It moves materials against the concentration gradient from lower to higher concentration and uses transport proteins and chemical energy.

What is the process of endocytosis?

The process of taking liquids or fairly large molecules into a cell by engulfing them in a membrane, forming a vesicle.

What is phagocytosis?

A type of endocytosis in which the cell membrane engulfs large particles.

What are the three components of a nucleotide in DNA?

DNA is a double stranded molecule made of four different subunits called nucleotides.

What are histones?

A group of proteins associated with chromosomes.

What are the functions of telomeres?

They are structures at the ends of DNA molecules that prevent ends of chromosomes from sticking to each other and help prevent the loss of genes.

What happens during the interphase stage?

The cell prepares to divide and by the end contains two full sets of DNA and is large enough to divide.

What is the result of mitosis?

It divides the cell's nucleus into 2 genetically identical nuclei, each with a full set of DNA.

What are the three parts of the Cell Theory?

1. All organisms are made of cells. 2. All existing cells are produced by other living cells. 3. The cell is the most basic unit of life.

What are the three parts of a phospholipid?

Glycerol, charged phosphate groups, and two fatty acid chains.

What is the function of cholesterol in the cell membrane?

It strengthens the cell membrane.

What is the fluid mosaic model?

The arrangement of molecules that make up a cell membrane.

What is the difference between an intracellular receptor and a membrane receptor?

An intracellular receptor is inside the cell and binds to molecules that cross the membrane; a membrane receptor binds to molecules that cannot cross the membrane and sends a message to the cell interior.

What are carcinogens?

Substances known to produce or promote the development of cancer.

How do cancer cells differ from healthy cells?

Cancer cells continue to divide even when surrounded by neighboring cells, do not perform specialized functions, and divide in the absence of growth factors.

What is apoptosis?

Programmed cell death that occurs when internal or external signals activate genes to produce self-destructive enzymes.

What limits the upper size of a cell?

The ratio of cell surface area to volume; volume increases faster than surface area.

What are the three components of the cytoskeleton?

Microtubules, intermediate filaments, and microfilaments.

What are the functions of the Smooth ER and Rough ER?

The Smooth ER has no ribosomes and makes lipids; the Rough ER contains ribosomes and makes proteins.

What is the function of the Golgi Apparatus?

Closely layered stacks of membrane-enclosed spaces that process, sort, and deliver proteins.

What are two unique characteristics of mitochondria?

They generate and provide energy to the cell and have their own ribosomes and DNA.

What is the role of lysosomes?

They are membrane-bound organelles with enzymes that defend the cell from bacteria and viruses and break down damaged cell parts.

What is the conclusion of Griffith's experiments?

Some material was transferred from heat-killed S bacteria to live R bacteria.

What were Chargaff's rules regarding DNA bases?

$A = T$ and $C = G$.

What is the first step of DNA replication involving helicase?

Helicase unzips the double helix at origins of replication by breaking hydrogen bonds, separating the original molecule and exposing bases.

What is an operon?

A region of DNA including a promoter, operator, and one or more structural genes that code for all proteins needed to do a specific task.

What is the difference between a point mutation and a frameshift mutation?

A point mutation is the substitution of one nucleotide for another; a frameshift mutation is the insertion or deletion of a nucleotide which affects the polypeptide more.

How do DNA and RNA differ in their structure and bases?

DNA contains deoxyribose, has the base T, and is double stranded; RNA contains ribose, has the base U, and is single stranded.

What is the function of tRNA?

It brings amino acids from the cytoplasm to a ribosome to help make a growing protein.

What are the three steps of translation?

1. Exposed codon attracts complementary tRNA with an amino acid. 2. Ribosome helps form a peptide bond between amino acids. 3. Ribosome pulls mRNA strand the length of one codon and the tRNA leaves the ribosome.

What is the purpose of PCR?

A technique that produces millions of copies of a specific DNA sequence.

On what is DNA fingerprinting based?

Noncoding regions of DNA or DNA outside genes.

What is recombinant DNA?

DNA that contains genes from more than one organism.

light dependent reactions function

capture energy from sunlight to make atp and nadph

calvin cycle function

turns energy captrued from light-depedent reactions to make simple sugars

photosystems

two groups of molecules where energy is captured and transferred in thylakoid membrane

electron transport chain

group of proteins in membrane of thylakoid that transfers energy across thylakoid

glycolysis function

glucose too large to continue to krebs cycle

begin celllular respiration, makes pyruvate

krebs cycle function

continue breaking down products of glucose and capture mroe energy

provide electrons for electron transport chain

electron transport chain function

produce most of the atp in cellular respiration using energy from nadh and fadh2