PH 120 Lec_TM2

What are the microscopic fundamental units of all living things?

Cells

Approximately how many cells compose an adult human body?

$100$ trillion cells

How many different types of specialized cells are found in the human body?

About $200$ different types

What is the sequence of the levels of structural organization in humans?

Chemical → cellular → tissue → organ → system → organismal

What term refers to a collection of cells that function together to perform the same activity?

Tissue

What is formed when masses of tissue work collectively to perform specific functions in the body?

An organ

What are the structural components within a cell that allow it to maintain life?

Organelles

What is the name of the gelatinous matrix in which organelles are suspended?

Cytoplasm

Which human cells are noted for lacking almost all organelles?

Red blood cells

What is considered the master control of the cell containing genes and DNA?

The Nucleus

Which non-membrane-enclosed structure within the nucleus is the site where ribosomal RNA is transcribed and assembled?

Nucleolus

What is the composition of the double-layered cell membrane?

Protein and lipids

What is the function of the lipid molecules in the cell membrane?

They allow the membrane to selectively transport substances in and out of the cell

What membranous structure consists of a network of tubules and vesicles for isolating and manufacturing substances?

Endoplasmic Reticulum (ER)

Which organelle is a stacked collection of flat vesicles that stores and converts products from the ER?

Golgi Apparatus

Which organelles contain enzymes for the digestion of nutrients and the breakdown of debris or bacteria?

Lysosomes

What is a secretory vesicle?

A vesicle containing enzymes that are emptied outside of the cell

Which organelle uses hydrogen peroxide to neutralize toxic substances and is formed from the ER?

Peroxisomes

What organelle is known as the powerhouse of the cell because it produces ATP?

Mitochondria

What structures make up the centrioles and mitotic spindles during cell division?

Microtubules

What is the central component of cilia and the specialized cilia found in the tail of sperm cells?

Microtubules

What are the two main layers or parts that make up a phospholipid molecule in the plasma membrane?

Polar hydrophilic heads and nonpolar hydrophobic tails

What is the liquid found inside the cell called?

Cytosol

What is the liquid found outside of the cell called?

Interstitial fluid

Which membrane transport process does not require energy expenditure?

Passive transport

Which membrane transport process requires the cell to expend energy?

Active transport

What is the movement of a substance from high concentration to low concentration?

Diffusion

What occurs when there is a difference in concentration between two areas?

A concentration gradient

What type of diffusion involves small and nonpolar solutes moving directly through the plasma membrane?

Simple Diffusion

What are examples of substances that move via simple diffusion?

$O_{2}$, $CO_{2}$, and small fatty acids

What form of diffusion is assisted by plasma membrane proteins for small charged or polar solutes?

Facilitated Diffusion

What type of channel in channel-mediated diffusion is continuously open?

Leak channel

What type of channel requires a stimulus to open for a short time?

Gated channel

What type of transport involves carrier proteins changing shape to move small polar molecules like glucose?

Carrier-mediated diffusion

What is the passive movement of water through a selectively permeable membrane?

Osmosis

What are the integral protein water channels called?

Aquaporins

In which direction does water move during osmosis relative to the solute concentration?

Water moves towards areas of greater concentration of solutes

What transport process moves a solute against its concentration gradient using ATP?

Primary Active Transport

What is a major example of an ion pump used in primary active transport?

$Na^{+}/K^{+}$ pump

How is energy provided in secondary active transport?

Utilizes energy from the movement of another substance down its concentration gradient

What is a symport mechanism?

Two substances moved in the same direction

What is an antiport mechanism?

Two substances moved in the opposite direction

What is an example of a symporter mentioned in the notes?

Glucose-sodium symporter

What is an example of an antiport exchanger mentioned in the notes?

Sodium-hydrogen exchanger

What is vesicular transport?

Transport of large substances across the plasma membrane via a vesicle

Which process involves materials being secreted from inside the cell to the outside?

Exocytosis

Which organelle produce the vesicles used in exocytosis?

Golgi apparatus

What is the term for 'cell eating' involving the fusion of a vesicle with a lysosome?

Phagocytosis

What is 'cell drinking', where the plasma membrane folds inward to take in interstitial fluid?

Pinocytosis

What type of endocytosis uses specific receptors on the outside of the plasma membrane?

Receptor-mediated endocytosis

What are prokaryotic cells?

Primitive single-celled organisms lacking membrane-bound genetic material and organelles

Where is the single circular DNA found in a prokaryotic cell?

The nucleoid

What are the subunits of the $70S$ prokaryotic ribosome?

$50S$ and $30S$ subunits

What is the glycocalyx?

An outer carbohydrate layer serving as protection and crucial for pathogenicity

What are the two types of glycocalyx?

Capsule (tightly-bound) and slime layer (loose)

What are plasmids?

Independent, self-replicating circular DNA that carries survival genes

How can plasmids be transferred between prokaryotes?

Conjugation (horizontal gene transfer)

What is the function of the prokaryotic flagellum?

Locomotion

What are pili specialized for?

Twitching motility and conjugation (sex pilus)

What are fimbriae used for?

Attachment to surfaces and host cells

What organelle is the site of photosynthesis in plant cells?

Chloroplast

What structure in plant cells maintains turgor pressure and is much larger than in other organisms?

Vacuole

What is the plant cell wall made of?

Cellulose

What organelle in plants forms and stores starch and helps with gravitropism?

Amyloplasts

While animals store energy as glycogen, how do plants store energy?

As starch

What structures regulate the passage of molecules between the nucleus and the cytoplasm?

Nuclear Pores

What is the nuclear envelope?

A double-membrane structural barrier composed of inner and outer lipid bilayers

What are the subunits of the $80S$ eukaryotic ribosome?

$60S$ large subunit and $40S$ small subunit

What is the function of intermediate filaments?

Maintains cell shape, bears tension, and anchors the nucleus and organelles

What is the study of body function?

Physiology

What is the study of body structures?

Anatomy

What is homeostasis?

The regulation and maintenance of our internal environment at conditions optimal for physiological processes

In which direction does DNA replication move?

$5'$ to $3'$

Why is DNA replication termed semi-conservative?

Because each new DNA copy is half original and half new

What are the four nucleotide base pairings in DNA?

$A-T$ and $G-C$

What is mitosis?

Somatic cell division producing two identical daughter cells

What happens during the Metaphase stage of mitosis?

Chromosomes line up at the midline of the cell (metaphase plate)

What occurs during the Anaphase stage of mitosis?

Spindle fibers separate chromosomes into sister chromatids and pull them to opposite poles

What is meiosis?

Reproductive cell division producing $4$ daughter cells with half the number of chromosomes (gametes)

What are haploid cells?

Daughter cells with half the number of chromosomes

Describe the Central Dogma of biology as mentioned in the notes.

DNA is transcribed into mRNA, which is then translated by a ribosome into protein

What is a codon?

A sequence of three nucleotide base pairs on mRNA that codes for a specific amino acid

What are the three main stages of cellular respiration?

Glycolysis, Krebs Cycle, and Oxidative Phosphorylation

Where does glycolysis occur?

In the cytoplasm

What is glucose turned into during glycolysis?

Pyruvate

Which stage of cellular respiration produces the most ATP and requires oxygen?

Oxidative Phosphorylation

Under anaerobic conditions, what can pyruvate be fermented into?

Lactic acid or ethanol

What is a hypertonic solution relative to a cell?

A solution with a greater concentration of solutes outside the cell, causing water to move out

What is a hypotonic solution relative to a cell?

A solution with a greater concentration of solutes inside the cell, causing water to move in

What cell type is specialized for protection, secretion, and excretion and covers body surfaces?

Epithelial cells

Which cells are specialized to initiate and conduct electric signals?

Nerve cells

Which type of muscle cell is long, striated, and attached to bones for voluntary movement?

Skeletal muscle

Which muscle type is found in the heart and contains intercalated disks?

Cardiac muscle

Which muscle type is spindle-shaped and non-striated, found in internal organs?

Smooth muscle

What tissue type is responsible for connecting, anchoring, and supporting structures and contains a large extracellular matrix?

Connective tissue

What liquid circulates in the body to supply food and remove wastes?

Plasma

Which body system takes up $O_{2}$ and eliminates $CO_{2}$?

Respiratory system

Which system regulates the amount of water and minerals in the body?

Urinary system

What is the function of the Integumentary system?

Protection, temperature regulation, and housing sensory receptors

Instead of pinching during plant mitosis, what structure forms to split the cell in two?

A cell plate