General things to know

What is anabolism?

small molecules are built into larger ones; requires energy.

What is catabolism

larger molecules are broken down into smaller ones, releases energy.

Enzymes

control rates of both catabolic and anabolic reaction

are special proteins that speed up chemical reactions in the body.

They help reactions happen faster by lowering the energy needed to start them.

Each enzyme works with one specific substance (called a substrate), like a key fits a lock.

The enzyme's shape (especially its active site) is what allows it to match with the right substrate.

Enzymes are not used up in the reaction — they can be used over and over again.

What factors increase the rate of enzyme-controlled reactions?

temp, substrate, enzyme, and pH

What is a major function of these vitamins in the body?

to act as biological catalysts that speed up crucial chemical reactions in the body by lowering the required activation energy

What is lactase?

is an enzyme produced in the small intestine that breaks down lactose, the sugar in dairy products

What is ATP? Why is it important?

is a nucleotide that consists of adenine, ribose, and three phosphate groups carries energy in a form the cell can use.

Main energy-carrying molecule in the cell; energy from ATP breakdown is used for cellular work.

What is cellular respiration?

the process by which cells convert glucose from food and oxygen into usable energy in the form of ATP

What are anaerobic reactions?

 do not require O2, and make little A T P.

What are aerobic reactions?

require O2, and make most of A T P.

What is Glycogen?

is a form of glucose, a main source of energy that your body stores primarily in your liver and muscles.

Structure of DNA

2 nucleotide chains, twisted into a double helix

Each nucleotide consists of a 5-C sugar (deoxyribose),

a phosphate, and a nitrogenous base (adenine,

guanine, cytosine or thymine)

Hydrogen bonds hold the bases together

Bases pair specifically (A ̶ T and C ̶ G); this is called

Complementary Base Pairing

DNA wraps around histone proteins to form

Chromosomes.  

Structure of DNA replication

replication fork, The Y-shaped structure where the DNA double helix is unwound and the two strands are separated by enzymes. 

What are the functions of proteins?

acting as enzymes to catalyze reactions, providing structural support for cells and tissues, and transporting molecules

Know how a protein is made

through a two-step process called protein synthesis, starting with transcription in the nucleus, where a gene's DNA is copied into a messenger RNA (mRNA) molecule. The mRNA then travels to the cytoplasm and attaches to a ribosome, where translation occurs, with transfer RNA (tRNA) molecules delivering specific amino acids to build a polypeptide chain based on the mRNA sequence

How do the processes of transcription and translation differ?

Transcription is the biological process of creating an RNA copy from a DNA template, while translation is the biological process of synthesizing a protein from an mRNA template

Know how to go from DNA to mRNA.

the process is called transcription, where the enzyme RNA polymerase creates a complementary mRNA strand from a DNA template

What is a codon? Why is it important?

Each amino acid is specified by a sequence of 3 bases in DNA.

acts as the fundamental unit of the genetic code, dictating the order of amino acids in a protein, which in turn determines the protein's structure and function.

What is an anti-codon?

a three-nucleotide sequence on a transfer RNA (tRNA) molecule that is complementary to a specific three-nucleotide codon on a messenger RNA (mRNA) strand

What is the genetic code?

the set of rules by which a cell's genetic material (DNA or RNA) is translated into proteins

Know the structure of RNA

a single strand of nucleotides, each with a phosphate group, a ribose sugar, and one of four bases: adenine (A), uracil (U), cytosine (C), or guanine (G)

-shorter than DNA

What is mRNA?

 Carries genetic code from D N A to ribosome.

what is tRNA

binds to its amino acid, transports it to a ribosome,

binds to the mRNA according to its sequence, and adds its

amino acid to the growing polypeptide chain.

What is a mutation?

Changes in the DNA sequence (Mutations occur when  bases are changed, added, or deleted

Know the four basic types of body tissues.

1. Epithelial tissue

2. Connective tissue

3. Muscle tissue

4. Nervous tissue

What is a desmosome?

Bind cells by forming “spot welds”

between cell membranes.

What is  a gap junction?

Form tubular channels between cells

that allow exchange of substances.

a tight junction?

Close space between cells by fusing

cell membranes

the blood-brain barrier

is a highly selective semipermeable membrane that separates the blood in the circulatory system from the extracellular fluid of the brain. 

What are functions of epithelial tissue?

• Covers organs and body surface.

• Lines cavities and hollow organs.

• Make up glands.

• Have a free surface on the outside, and basement membrane on the inside.

• This tissue lacks blood vessels (avascular) and nutrients diffuse to epithelial

tissue from underlying connective tissue.

• Cells readily divide; injuries heal rapidly.

• Cells are tightly packed.

• Classified according to cell shape and number of cell layers.

Stratified squamous epithelium

Function: Protection

Location:

• Skin (keratinized)
  
  

• Mouth, oral cavity
  
  

• Vagina
  
  

• Anal canal
  

Simple squamous epithelium

• Function: Diffusion & filtration
  
  -Location:
  
  

  • Air sacs in lungs (alveoli)
    
    

  • Capillaries (walls)
    
    

  • Blood and lymphatic vessels
    
    

Simple cuboidal epithelium

• Function: Secretion & absorption
  
  

• Location:
  
  

  • Kidney tubules
    
    

  • Thyroid follicles
    
    

  • Ovaries
    
    

Ducts of some glands

Simple columnar epithelium

Function: Secretion & absorption
Location:

• Stomach
  
  

• Intestines
  
  

Uterus

pseudostratified columnar epithelium,

Function: Protection; moves mucus

• Location:
  
  

  • Respiratory tract (e.g. trachea, bronchi)
    
    

Transitional epithelium

• Function: Stretchable, protects and allows expansion
  
  

• Location:
  
  

  • Urinary bladder
    
    

  • Ureters
    
    

  • Part of urethra

areolar tissue

• Function: Binds organs
  
  

Location: Beneath the skin, between muscles, beneath epithelial tissues

Fibroblasts

Characteristics: Widely distributed, large, star-shaped cells

Dense Regular Tissue

 Closely packed collagenous fibers.

• Fine network of elastic fibers.

• Most cells are fibroblasts.

• Very strong, withstands pulling.

• Binds body parts together.

• Tendons, ligaments, dermis.

• Poor blood supply; slow to heal.

Dense irregular tissue

• Randomly organized, thick,

interwoven collagenous fibers.

• Can withstand tension exerted from

different directions.

• Dermis of skin.

• Around skeletal muscles.

Hyaline cartilage

• Most common type.

• Fine collagen fibers.

• Ends of bones in joints Nose,

respiratory passages.

• Embryonic skeleton.

Elastic cartilage

• Flexible, due to elastic

fibers in matrix.

• External ear, larynx

Fibrocartilage:

• Very tough, due to many collagenous fibers.

• Shock absorber.

• Intervertebral discs.

• Pads of knee and pelvic girdle.

Osteons

• Osteons are cemented together to form compact bone.

central canals

Central canals contain blood vessels; bone is well-nourished, heals more quickly than

cartilage

lacunae

small cavities or depressions in the bone or cartilage matrix where cells, such as osteocytes (in bone) or chondrocytes (in cartilage), reside

canaliculi

microscopic channels in bone tissue that connect the spaces (lacunae) where bone cells (osteocytes) are located

Osteoc

to the bone cells osteoclasts, which break down and resorb (dissolve) bone tissue as part of the continuous process of bone remodeling and repair

What is Elastic connective tissue and where is it found.

a type of dense connective tissue that contains abundant elastic fibers, giving it the ability to stretch and recoil

What is the function of adipose tissue?

Protects, insulates, stores fat

Which muscle tissues are under involuntary control?

Smooth, Cardiac, 

Smooth muscle

Cell Shape: Shorter cells, no striations, single central nucleus

Control: Involuntary

Function: Moves internal organs

Location: Walls of hollow internal organs (like stomach, intestines, blood vessels)

skeletal muscle cells

long, multi-nucleated, and striated cells responsible for voluntary movement. They are found attached to bones throughout the body and function to move the skeleton, maintain posture, generate heat, and stabilize joints. 

Cardiac muscle cells.

located in the heart wall, their main function is to involuntarily contract to pump blood throughout the body, and they are structured with branched fibers, striations, a single or two central nuclei, and intercalated discs that contain gap junctions and desmosomes for coordinated contraction. 

Cardiac muscle cells.

found exclusively in the heart's middle layer (myocardium) and function involuntarily to pump blood by contracting in a synchronized, rhythmic manner

What are the characteristics of nervous tissue?

Cell Shape: Cells with cytoplasmic extensions (like branches)

Function: Sensory reception, sending electrical impulses, releasing neurotransmitters

Location: Brain, spinal cord, and peripheral nerves